When you get into the game choose - Quick Play.
Might have to wait a few seconds to join a lobby, usually after about a minute or two and if you haven't joined a lobby cancel and try again.
Once you join and ready up,you will get into the game. Thats not all however, you MUST finish the match!! Stay and watch even if you die early, you have to stay until jason kills everyone or all the counselors escape and you get to the screen where points are divided up. It should pop.