1. You already have a good gun so know how to use it - practice snapshooting, shooting offhand, staying tight in your bunker, how to fix common problems (especially on-field problems like bolt stick or a chopped ball)
2. Before the tournament, practice as a team - learn each players style (who's aggressive, who sits back, etc) and know what positions you're going to play
3. Work on your communication - create some basic codes for eliminations, movement, gun down and use them in practice
4. read PGI and the forums for drills, advice, etc.
5. (most important) HAVE FUN!
Don't expect to conquer the world in your first tournament. Try to learn something from each game. Talk to teams after you play them and see if they'll give you some pointers.