Everybody has his or her own way to relax. Just remember that no one is going to be keeping tabs on you. Your purpose is to play your game.
People will remember you when you start dominating the field and making everything happen, not when you are learning/ doing poorly. Performance anxiety is totally misplaced. If you are sucking, people will not care who you are, so don't worry about how it looks, worry about remembering what to change in your game. Learn for now, you are paying, it is your tournament, get your money's worth out of the opportunity to play a wide variety of players with different skill levels and styles in a field that is (hpefully) unfamiliar.
Watch other teams as much as you have time to. If a team is doing something that works, steal their good ideas shamelessly. If a team you're about to play breaks three players to the right, get guns up to lane them back to their 'box.
Have fun. That and pride are the only things riding on this.