You're young, and you hopefully have the brains to go to university (since you're planning on that). I'd wait until after the exams are done with school, save up money, and go to the airfield every day. Bring a textbook. If the wind or clouds are unfavourable, sit and read.
I didn't do any reading away from the airfield; I just went there 5 days a week for a few weeks, read while waiting for planes to come back etc, and didn't have any problems with the theory. It's not really that hard.