1. What is your normal stuff? You should make sure your mag springs are in good shape. Have stuff to take them apart and clean them. Bring your cleaning kit, squib rod. Extra batteries for muffs and/or red dot. Sweat rag, glass cleaner. Rain gear just in case. Lots of water & snacks.
2. Jumping the buzzer, equipment position for your division, etc. Read your division rules as stated above.
3. Shoot within your skill level, relax, shoot clean(you can win your class/division with consistency) make sure belt, mag pouches, holster are all secured with no loose or missing screws etc., thourouly clean gun (I tear mine down 100% once a month to clean firing pin extractor, etc. All that stuff that a normal cleaning doesn't get) remember that what can go wrong sometimes will go wrong, on the bigger match. Have FUN !! BE SAFE!!!