I always go for two day events if possible. Getting to sleep on what you learned and going out the second day really helps a lot. Your first couple sessions may feel like information overload but it won't be long before you start to put it all together.
I'm not familiar with those specific tracks... but I started on what is the most dangerous track in my area (Waterford Hills Road Racing. Lots of walls and gators) in a really terrible rain. Just give yourself more margin and try to relax.
Your instructors will help with that.
I'll bet you $100 you are hooked after the first session. I would keep the car as stock as possible for probably the first year (unless you really start driving the wheels off of it!) then looking at correcting whatever deficiencies you find. That does
NOT include running better brake fluid (super blue, motul rbf600, etc), upgraded brake pads, and an oil cooler.
Do the brake stuff before your first track event and be ready to want an oil cooler before your next!
Don't hesitate to ask any other questions. I'd take a look at some of the other "first time HPDE" threads here too.