Tycho you mean? Unless this tournament has a rule that lets you take pilots in different ships (in which case it's time to break the game)?
Anyway, two pieces of advice:
1) Fly ships you're comfortable with. The power gap in X-Wing isn't so big that you can win purely on list strength, a well-flown "weak" ship is much better than a "strong" ship you don't know how to fly properly. Don't take
bad ships/upgrades, but if you've been having success with a particular list then keep doing it.
2) Understand how the extra 50 points changes the metagame. More ships on the table means fewer places for arc dodgers (phantoms, interceptors, etc) to hide, more cases of focused high-
PS shooting killing low-
PS ships before they can return fire, less space for swarms to maneuver, etc. As a new player this means keep your total number of ships down (no more than three per player, or one small + one large) and don't take any fragile arc dodgers.