I would leave the comma out: if the two sentences were written as a single sentence, there would be no comma: "Moreover, I have completed my senior secondary studies in English and won 1st place at the regional stage of English Olympiad, so I am confident that I will be able to complete a degree in English." This is fairly formal English.

I'd reserve commas after so only when so seems to come out of nowhere: "So, are you coming or not?" A woman walks into the living room and asks, "So, how do you like my new dress?" This is hardly formal English.

I am not sure whether to put a comma after "so", which is at the beginning of a sentence
Are achievements in Skyrim per character or per account on steam? If the Achievements are per account is there a way I reset them?

When I say per character I mean can the Achievements I earn on one character be re-earned with another character?
