Sounds exciting.
You don't have to worry about him losing the first round and then not getting to play. Redemption is awesomer than that beings it uses the swiss system; even if you lose every round, you still get to play the same number of games as everyone else! Just try and build him a simple deck until he gets a further grasp on the game: 1 good color, 1 evil color (I reccomend 8 heroes, 8 good enhancements, 8 evil characters, 8 evil enhancements, 7 lost souls, and then sites/forts/curses/whatever else helps).
As for teams, just make sure your defense help each other. If one of you is playing demons, make sure the other isn't using three nails
.