my first win
2... c5 isn't a common move but aside from bringing the queen out early, it seems fine.
8 f3 wasn't good because it weakens the pawns around the king and the knight will have to be moved anway. The knight ends up being lost without compensation, in fact it further helps black by putting his bishop on a good diagonal.
12 b4 wasn't too good, although it wins a knight for two pawns, it also helps clear the way for black to give checkmate. Better would be 12 Qd3, forcing a queen exchange that will slow down black's attack.