Check with your sponsoring club. At the Divisional and National level, drivers must be SCCA members to compete. Here are some dos and don'ts for autocrossers, rookies and veterans alike. If your car is stock, and you intend to race it on your street tires, all you really need is your car, a helmet , a tire pressure gage, and your entry fee. The very first time you go, you will probably want to bring some of the stuff listed in this checklist .
Some people like to be prepared for anything.
Depending on your involvement in the sport, your needs will vary. There is much advice to be gained from Team. Several of these items are hypertext links to some of that advice regarding that item. The helmet can be full face, open face, or open with a chin guard. These are more commonly available and less expensive.