First thing you do is go to registration. Tell them you're a novice, like DakarM said. If they don't have an obvious TECH sign or place, ask them where tech is (that's where they check to make sure your battery's tied down, your throttle return works, and you remembered to tighten your wheel lugs). If you haven't already, take all loose items out, including floor mats. Once the car is tech'ed, the next thing you'll have to do is walk the course. Just wait for the heat that's running to finish. There might be a novice walk through, so you might wanna ask at registration.
For complete details, see CivicSiRacer's help page.