Park near someone with an enclosed trailer.
Make friends with those in big popup tents.
A friend of mind has a big fan to keep cool.
Store your gear in something that will protect it from wind and rain.
A lot of people use tarps.
I use a tent and throw all my stuff in there.
Then I don't have to worry about wind or rain.
Peace of mind.
For tools you really don't need to get carried away.
There are always people around to give you a hand.
Air gauge, torque wrench.
Oil
Lots of Water or Gatorade.
Windshield cleaner and paper towels.
Maybe work gloves.
If you are going to shoot video, it's a good idea to be able to view your hand movement as well as car position.
First time, don't get overwhelmed.
Be safe
Learn
Have fun
For me it was overwhelming at first.
Now I find it relaxing.
bf.c has a good track forum.