Choose your pistol and a good holster. You'll want several mag carriers as well. There is no practice, other than you are allowed to walk through and assess the individual stages before the group starts. You can figure where and from what position you'll shoot from, be able to see all the targets and their positions, and maybe count your shots and figure where your tactical reloads will need to take place. Our club does IPSC, but it's similar. Under USPSA, there are a few classes such as limited 10 (ten round mags only), production (any modern hi-cap pistol/mags), and single stack (1911's mainly or SIGs and such with single stack mags), and minor (9mm) and major (40S&W and over) categories to shoot in. If you're shooting some steel target stages...definitely bring more ammo than the match lists....for instance, match xxxxx, 176 total round count...these are good hits on target and the count won't include misses....yes, you can shoot 300 rounds in a stage or until you run out of ammo or full mags...you're only going against yourself and the clock. First time...bring twice the ammo of the total round count, and just go to learn and have fun, and be safe. Safety will be reiterated numerous times. Your muzzle should never go past 90 degrees either side of you facing down range. I've seen one guy get disqualified for spinning around after engaging a target in the sixth stage of an eight stage match. Good luck.