Patman;

I was 16 when I started tinkering with cars (if there were no girls around). That was 40 yrs ago. <sigh>. In addition to what Tom wrote, you could go to the local library to get started. Don't try and cram too many areas (engine, trans, ect) at once. Start with the basics. I remember reading a book MANY years ago that explained exactly how an engine runs. Once you understand the basics, the rest will come much easier. Then, you can move on to another area. Just a thought, but today's vehicles are getting more and more electrically complicated. The electrical side of repair is where the most money is. And, your hands stay clean. The engines still go back to that original basic knowledge, but...And, with technology changing so fast, us old farts will be out of the picture in a very few years. People are going to depend on you young guys to fix the problems. Our local high school has a work experience program. We have, usually a Jr. or a Sr. come to our shop for a semester or two to get a "feel" of what it's like. Might check with your school. Good luck. Good learning.
Loren
SW WA