I know it can seem overwhelming, getting everything done in time. That's why I'd recommend renting for the school. The school will be a full two day affair, where you'll have to attend class sessions between on track sessions. If you are still set on driving your own car, you'll at least need someone to crew for you as you won't even have time to gas up and go. I'm a one-man-band type racer and besides my car wasn't ready yet, so I went the rental route. There were several people in my school who drove their own car, those who were seccessful had a crew person. As for a log book, as long as you have an experienced person prepare your car, you should be able to get the log book on the morning before your first run. If you're doing the preperation yourself expect to not pass tech and have some fixing to do, and not make it through the school. BTW, for more indepth answers Cal Club has a "getting started" forum too:

http://www.calclub.com/forums/index.php?showforum=4