Battery is the big one for tech inspection, along with no leaks, good belts and lug nuts torqued down. I'd also ditch the spare tire once there and floor mats if you have them. Like said anything loose that you don't need. Since you have the helmet already, see how you fit with it on in the car. Some people have to really change the way they normally sit to fit right with the extra height the helmet adds. Your instructor should walk you through the course, memorize it in your head and replay it over and over.
Other than that, just relax and have fun! It's addictive and you'll be surprised how much you'll learn about you and the car.
