E-town is an NHRA track.
If your car is stock, or close to stock and facotry prepped, you will get past tech pretty easily. When you start adding parts and going faster, tech becomes more detailed. (Basically they look at your car and check if it meets NHRA specs.)
You need a helmet if you run any quicker than 13.99. I suggest you run one anyway. You can purchase a cheap one, or a good one off of ebay that is out of cert for cheap. Clean it up and go. You need to look at safety as not your car, but the other car. I have never been out of my lane. I run out of fingers with how many cars have been in my lane. I have three full crashes and many near misses in the other lane. Two of the crashes, crashed in MY lane. This stuff does happen. Get a helmet.
You need a roll bar if you go quicker than 11.99, or a certified roll cage is quicker than 10.99. (If you are in a convertable, you need a roll bar at 13.99.) If you go quicker than 11.99 with a stick, you need a certified scatter shield. 13.00 and quicker you need a driveshaft loop on street tires. That is about all the general regs you will run into. Later you can get into the parachute manidtory at 150 mph etc.
Just go watch a few races to see how staging goes, and how the track works. then jump in your car and give it a whirl. Never roll treaded tires through the water. Drive around and back in if you want to get wet, or just drive around and hop it once in the dry to clean the tires off. With a WRX and radials, a burnout will do more harm than good.
Oh yeah, wear long pants. It will be about $10 bucks to race. (At least that is what it is around here.) Anyone with legal state drivers license can run a street car.