I really like circuit training. 10 1 minute stations, 15 rest between each station, 2 minutes rest between each round.
Do you have a game plan yet? Are you going to pull guard or have you been working on your take downs? The best advice I can give is relax and play your game. Don't worry about points too much, just focus what you need to do in the position you're in. No matter how well you prepare your first tournament is a pretty crazy experience, an adrenaline dump and butterflies at the same time is intense. I only remember flashes of my first tournament.
Also a few days away from your tournament you may get some pre competition jitters. Whenever I start to feel nervous about it I just visualize the match and everything I do works. I go for the double, they can't stop it, I pass their guard easily, etc. This has helped me relax quite a bit.