In addition to what Arne said, you may have to shoot more arrows than you're used to. Here in the west, we usually shoot about 84 arrows during the tournament, plus whatever you shoot warming up probably makes a total of about 100 arrows. My impression is that they shoot fewer arrows in east coast tournaments, but I don't know.
It would be nice if you could just shoot as long as you feel you're getting something out of it and then stop, but sometimes that can be hard to do if you're with a group of people you know. Later on, part of the challenge of shooting in a tournament is recovering from lapses in form, and shooting as well as you can even when you're tired, but that's probably not the best learning experience.