Recently I started learning programming and I created this program. I've added something to it with every new lesson.How is my code-writing?  Do I make mistakes I shouldn't make?The program itselfstatic void Main()    {        {            Console.WriteLine(Select language:\n);            Console.WriteLine(1. Bulgarian);            Console.WriteLine(2. English\n);            Console.Write(Number: );            byte language = byte.Parse(Console.ReadLine());        //....        //Skipped to        //English        if (language == 2)        {            Console.Clear();            string restart = Press any key to exit the program...;            Console.CursorVisible = true;            string chislo = Please press the number that corresponds to the function:;            Console.WriteLine(chislo);            Console.WriteLine();            Console.WriteLine(1. Balance calculator);            Console.WriteLine(2. Calculating numbers);            Console.WriteLine(3. Comparing numbers);            Console.WriteLine(4. Time and Date);            Console.WriteLine(5. Calculation of the number of words and characters from a text/sentence \n);            Console.WriteLine(Settings:\n);            Console.WriteLine(6. Change the color of the console \n);            Console.Write(Number: );            string chisloFunkciq = Console.ReadLine();            int chisloFunkciqParse;            if (int.TryParse(chisloFunkciq, out chisloFunkciqParse))            {                Console.Clear();                //Funkciq Saldo                if (chisloFunkciqParse == 1)                {                    Console.WriteLine(You chose \Balance calculator\ \n);                    bool check = true;                    while (check == true)                    {                        Console.Write(Enter the opening balance: );                        string nachalnoSaldo = Console.ReadLine();                        double chisloNachalnoSaldo;                        if (double.TryParse(nachalnoSaldo, out chisloNachalnoSaldo))                        {                            Console.WriteLine();                            Console.WriteLine(Your opening balance is {0:C} \n, chisloNachalnoSaldo);                        }                        else                        {                            Console.CursorVisible = false;                            Console.Clear();                            Console.Beep();                            Console.WriteLine(\{0}\ is not a number. Please try again. \n, nachalnoSaldo);                            continue;                        }                        //Prihodi                        Console.Write(Enter revenue: );                        string prihodi = Console.ReadLine();                        Console.WriteLine();                        double chisloPrihodi;                        if (double.TryParse(prihodi, out chisloPrihodi))                        {                            Console.WriteLine(Your revenue is {0:C} \n, chisloPrihodi);                        }                        else                        {                            Console.CursorVisible = false;                            Console.Clear();                            Console.Beep();                            Console.WriteLine(\{0}\ is not a number. Please try again.\n, prihodi);                            continue;                        }                        //Izrazhodvano saldo                        Console.Write(Enter consumption balance: );                        string izrazhodvanoSaldo = Console.ReadLine();                        Console.WriteLine();                        double chisloKrainoSaldo;                        if (double.TryParse(izrazhodvanoSaldo, out chisloKrainoSaldo))                        {                            Console.WriteLine(Your consumption balance is {0:C} \n, chisloKrainoSaldo);                        }                        else                        {                            Console.CursorVisible = false;                            Console.Clear();                            Console.Beep();                            Console.WriteLine(\{0}\ is not a number. Please try again. \n, izrazhodvanoSaldo);                            continue;                        }                        //Rezultat                        double rezultat = (chisloNachalnoSaldo + chisloPrihodi) - chisloKrainoSaldo;                        Console.WriteLine(The remaining balance is {0:C} \n, rezultat);                        check = false;                        Console.CursorVisible = false;                        Console.WriteLine(restart);                        Console.ReadKey();                        Console.Clear();                    }                }                // Funkciq Calculator                if (chisloFunkciqParse == 2)                {                    Console.WriteLine(You chose \Calculating numbers\ \n);                    double otgovor = 0;                    Console.Write(Please enter the first number: );                    double purvoChislo = double.Parse(Console.ReadLine());                    Console.WriteLine();                    Console.Write(Please enter a character (+, -, * ili /): );                    string znak = Console.ReadLine();                    Console.WriteLine();                    Console.Write(Please enter the second number: \n);                    double vtoroChislo = double.Parse(Console.ReadLine());                    switch (znak)                    {                        case +:                            otgovor = purvoChislo + vtoroChislo;                            break;                        case -:                            otgovor = purvoChislo - vtoroChislo;                            break;                        case *:                            otgovor = purvoChislo * vtoroChislo;                            break;                        case /:                            otgovor = purvoChislo / vtoroChislo;                            break;                    }                    Console.WriteLine({0} {1} {2} = {3}, purvoChislo, znak, vtoroChislo, otgovor);                    Console.WriteLine(restart);                    Console.ReadKey();                    Console.Clear();                }                //Sravnavane na chisla (2,3 ili 4)                if (chisloFunkciqParse == 3)                {                    Console.Clear();                    Console.WriteLine(You chose \Comparing numbers\ \n);                    Console.WriteLine(1. Comparing 2 numbers);                    Console.WriteLine(2. Comparing 3 numbers);                    Console.WriteLine(3. Comparing 4 numbers);                    int chisloBroi = int.Parse(Console.ReadLine());                    switch (chisloBroi)                    {                        case 1:                            int sravPurvoChislo;                            int sravVtoroChislo;                            int sravTretoChislo;                            int sravChetvurtoChislo;                            Console.WriteLine(You chose \Comparing 2 numbers\ \n);                            Console.Write(Please enter the first number: );                            sravPurvoChislo = int.Parse(Console.ReadLine());                            Console.WriteLine();                            Console.WriteLine(Please enter the second number: );                            sravVtoroChislo = int.Parse(Console.ReadLine());                            Console.WriteLine({0} is bigger than {1}, Math.Max(sravPurvoChislo, sravVtoroChislo), Math.Min(sravPurvoChislo, sravVtoroChislo));                            Console.WriteLine(restart);                            Console.ReadKey();                            Console.Clear();                            break;                        case 2:                            Console.Clear();                            Console.WriteLine(You chose \Comparing 3 numbers\ \n);                            Console.Write(Please enter the first number: );                            sravPurvoChislo = int.Parse(Console.ReadLine());                            Console.WriteLine();                            Console.Write(Please enter the second number: );                            sravVtoroChislo = int.Parse(Console.ReadLine());                            Console.WriteLine();                            Console.Write(Please enter the third number: );                            sravTretoChislo = int.Parse(Console.ReadLine());                            Console.WriteLine(The largest of these numbers is {0}, and the smallest is {1}, Math.Max(Math.Max(sravPurvoChislo, sravVtoroChislo), sravTretoChislo), Math.Min(Math.Min(sravPurvoChislo, sravVtoroChislo), sravTretoChislo));                            Console.WriteLine(restart);                            Console.ReadKey();                            Console.Clear();                            break;                        case 3:                            Console.Clear();                            Console.WriteLine(You chose \Comparing 4 numbers\ \n);                            Console.Write(Please enter the first number: );                            sravPurvoChislo = int.Parse(Console.ReadLine());                            Console.WriteLine();                            Console.Write(Please enter the second number: );                            sravVtoroChislo = int.Parse(Console.ReadLine());                            Console.WriteLine();                            Console.Write(Please enter the third number: );                            sravTretoChislo = int.Parse(Console.ReadLine());                            Console.WriteLine();                            Console.Write(Please enter the fourth number:  );                            sravChetvurtoChislo = int.Parse(Console.ReadLine());                            int purviIzraz = Math.Max(sravPurvoChislo, sravVtoroChislo);                            int vtoriIzraz = Math.Max(sravTretoChislo, sravChetvurtoChislo);                            Console.WriteLine(The largest of these numbers is {0}, and the smallest is {1}, Math.Max(purviIzraz, vtoriIzraz), Math.Min(purviIzraz, vtoriIzraz));                            Console.WriteLine(restart);                            Console.ReadKey();                            Console.Clear();                            break;                    }                }                //Funkciq Data                if (chisloFunkciqParse == 4)                {                    Console.WriteLine(Today is {0} \n, DateTime.Now);                    Console.WriteLine(restart);                    Console.ReadKey();                    Console.Clear();                }                //Funkciq Presmqtane na broi dumi i znaci ot tekst                if (chisloFunkciqParse == 5)                {                    Console.Write(Please enter a text/sentence );                    string izrechenie = Console.ReadLine();                    Console.WriteLine();                    int broiDumi = izrechenie.Split(' ').Length;                    int broiZnaci = izrechenie.Length;                    if (broiDumi == 1)                    {                        Console.Write(This text contains {0} word and , broiDumi);                    }                    else                    {                        Console.Write(The text contains {0} words and , broiDumi);                    }                    if (broiZnaci == 1)                    {                        Console.WriteLine({0} character, broiZnaci);                    }                    else                    {                        Console.WriteLine({0} characters, broiZnaci);                    }                    Console.WriteLine();                    Console.WriteLine(restart);                    Console.ReadKey();                    Console.Clear();                }                //Cvqt Konzola                if (chisloFunkciqParse == 6)                {                    bool check = true;                    while (check == true)                    {                        Console.WriteLine(Choose the number corresponding to the color you want:\n);                        Console.WriteLine(1. Red);                        Console.WriteLine(2. Green);                        Console.WriteLine(3. Yello);                        Console.WriteLine(4. Return to the previous settings (Black)\n);                        Console.Write(Number: );                        string cvqtChislo = Console.ReadLine();                        int cvqtChisloParse;                        if (int.TryParse(cvqtChislo, out cvqtChisloParse))                        {                            switch (cvqtChisloParse)                            {                                case 1:                                    Console.BackgroundColor = ConsoleColor.Red;                                    Console.ForegroundColor = ConsoleColor.Black;                                    Console.Clear();                                    Console.WriteLine(You chose red);                                    Console.WriteLine();                                    Main();                                    break;                                case 2:                                    Console.BackgroundColor = ConsoleColor.Green;                                    Console.ForegroundColor = ConsoleColor.Black;                                    Console.Clear();                                    Console.WriteLine(You chose green);                                    Console.WriteLine();                                    Main();                                    break;                                case 3:                                    Console.BackgroundColor = ConsoleColor.Yellow;                                    Console.ForegroundColor = ConsoleColor.Black;                                    Console.Clear();                                    Console.WriteLine(You chose yellow);                                    Console.WriteLine();                                    Main();                                    break;                                case 4:                                    Console.BackgroundColor = ConsoleColor.Black;                                    Console.ForegroundColor = ConsoleColor.Gray;                                    Console.Clear();                                    Console.WriteLine(You chose the default color (black));                                    Console.WriteLine();                                    Main();                                    break;                                default:                                    Console.CursorVisible = false;                                    Console.Clear();                                    Console.Beep();                                    break;                            }                            continue;                        }                        else                        {                            Console.CursorVisible = false;                            Console.Clear();                            Console.Beep();                        }                    }                }                if (chisloFunkciqParse > 6)                {                    Console.CursorVisible = false;                    Console.Beep();                    Console.Clear();                    Main();                }            }            else            {                Console.Clear();                Console.WriteLine(You did not specify a number. Please try again \n);                Console.CursorVisible = false;                Console.Beep();                Main();            }        }
Console-based menu system
c#;beginner;console