Get there early, so that you won't be rushed getting your car ready for tech inspection and dealing with the rest of the administrative matters.
Inspection - all loose objects need to be taken out, especially the floor mats. You may want to clean your windshield and top off your oil. They should check things like brake pedal feel, battery for being firmly secured, wheel bearings for looseness, no obvious fluid leaks, etc.
You will have to go through a registration procedure of some kind, and there will be at least one waiver that you'll have to sign (possibly on the way in to the lot). At some point there will be a drivers' meeting that you are required to attend.
Bring plenty of water (staying hydrated is important), and a snack or even a couple of sandwiches. Food may or may not be available on site, there may or may not be anything close enough, and a lunch break period may or may not be provided for in the day's schedule. As weather conditions suggest - something to sit on, sunscreen, umbrella, towels, jacket, hat, sunglasses. Better to come prepared.
Walk the course, preferably more than once. If there is any organized instructed course walk offered, tag along. If instructed runs (an instructor rides with you and provides help during your run and critique afterward) are available, take advantage.
Have fun. I hope that at least knowing about the above will make it easier for you to enjoy the event.
Norm