Спасибо!

Yes, I play the bass guitar (Да, я играю на басс-гитаре? My dictionary says it's in the prepositional case, so...) I'm better at playing bass than I am at speaking Russian

In the sentence "У тебя хорошо получается говорить по-русски", why is the 'У' there and why is говорить in the infinitive? I have a bit of a thirst for knowledge...