Hello Sketch and welcome to Halocustoms! First off welcome to the community, its a pleasure to have you and we're all fairly nice here. Secondly you may want to do as Jski said and RSVP to a game by clicking on the "Customs" tab at the top of this page and finding a game to join ^.^.
Anyway if you have any questions, just feel free to ask them and we'll answer best we can. Happy gaming .