Can i abandon a game? And what i get if a win a game?

I have 2 noob questions:

1 - if i join a game but i do not like the atmosphere and wanna quit, is this possible? Or i just put the game in archive and forget about that?

2 - let;s say a make the points for the winning, what i get if i winn a game? Gold or something?

Thx in advance !