If you want to win that first game, it helps to have the Jecht Shot.

Pass around the ball, keeping away from the opposing players until Tidus is near the opposing goalie. (I say keep away, because most of the Goers players will own those pitiful Aurochs in a matchup). Once Tidus is near, pass it to him, and if he's covered do the Jecht Shot, if he's open do the Sphere Shot. He'll only get to do this once per half, as both shots require a lot of hp.

In the second half, be sure to get tidus in for a shot early, as he leaves part ways in to let Wakka on. After that, just play "keep away".

After Luca, recruit the following:
RF: Wedge - the entrance to Luca Stadium.
MF: Brother - airship bridge
LF: Tidus
RD: Kyou - the bridge to Djose Temple
LD: Ropp - Mi'hen Travel Agency
Goal: Miyu - North Bank of the Moonflow

extra: Zalitz - a great defender until you recruit Kyou.
extra: Zev Ronso - a great MF until you recruit Brother

You'll be unbeatable.