It would be good if you can go with someone else who has another car so that you can store stuff in it. When you drive, the car can't have anything inside. No cooler, lunch, tools, not even floor mats! If you show up by yourself, you may be stuck not having anyone to hold your stuff.
Also, don't worry about trying to mod the car. Run it stock (at least for now
Definitely ask to have an instructor with you. It's easy to get lost in the sea of cones.
Make sure your battery is tied down and the positive post to the battery is covered. Any other thing (e.g., audio amps) needs to be bolted down.
Some small bungie cords can help secure things.