Hiya Wally, there are people booked in with the same car who will be happy to help set your car up and give you any advice you ask for.
You will need a transponder to race but there are "hand out" units available. You'll need a mounting position on the car but that wont take too long to sort out, most people will have something available to make one.
Not sure on the start time, that will be on the website - having your car ready to put on the track for 8.30 would be a good thing though.
As for hotels, there is a list on the website of places to stay nearby.
Bring a 6' table or keyboard stand, 12v leisure battery if you have one - 240v is in the pits but it's in limited supply. There is a great cafe and bar on site so some coin of the realm will be required.
The most important thing, is come with an open mind, be prepared to ask questions and introduce yourself to anyone and everyone. Don't come expecting to win - but don't think that just because you're new, you'll be walked all over.
Hope this helps, feel free to ask anytnig else.