Where do I start learning Higher Mathematics? I am 17 years old and I would like to begin learning Mathematics. I am only familiar with Algebra and a bit of Geometry. Do I need to learn Calculus next, or should I try linear algebra? I find myself very interested in number theory. Is there anywhere I can see some sort of tree that shows me prerequisites for different Mathematical studies. I also want to know if there are any websites or resources that can teach me Math formally, using proofs. In high school we never learned math formally or rigorously. Thanks.
Also any books I could get would be appreciated. Keep in mind I am trying to start off, I only know basic Algebra right now, like functions, polynomials, and systems of equations.

There are quite a few good sources out there for learning different fields in mathematics. Personally some of my favorates are:


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*http://ocw.mit.edu/courses/mathematics/

*https://www.khanacademy.org/math
To get started you need to know the learning path you will take, what classes and areas you want to begin with and proceed to. A basic path for general mathematics would be: (pipe shows what I feel can be learned at the same time)
Algebra I > Geometry | Algebra II > Statistics | Trigonometry > Linear Algebra > Single Variable Calculus > Multi-Variable Calculus | Differential Equations
From there you should be well versed enough to know what branch of mathematics you would like dive deeper into
