See if your school offers a class in Auto Tech, kinda like wood shop, or a Votech school. The schools in Pa let students have the opportunity to go to regular high school for half a day then bus them to a Votech school for half a day. The Votech schools teach trades like computer courses, Auto Tech, Auto Body, Cosmetology, etc.
Ask questions, don't be afraid to ask allot of questions if necessary.
Volunteer at shop as previously suggested. You can do a fair amount of reading on the net but be cautious, not everything you read is true.
One thing that is cheap for you to start with, go to a parts store and get the Chiltins Book for your car. It will have most, if not all, of the info for your car in it, trouble shooting, diagrams, etc.
Welcome and good luck.