I think most of us were born with a natural curiosity about mechanical things. It seems a little strange to me that you didn't get bit for 26 years. That doesn't mean you can't learn but I had more than 20 years of experience at your age. I started helping my dad work on his 34 Packard when I was 5.

I was always taking things apart to see how they worked and how they were designed. I decided early in life that I wasn't going to repair clocks or watches because I could never get them back together.

I spent my allowance and lawn mowing money on popular mechanics and popular science magazines that I read from cover to cover. When I was 10 I discovered hot rod magazines and I knew I could do that if I had more money.

When I was 12 I owned a 39 Olds coupe with no reverse gear and a 49 Ford coupe with no wheels. My tools were a screwdriver and a pair of pliers so not much was acomplished. When I had to move I sold the Olds for $30 and gave the Ford to a friend.
I spent the next few years working on bicycles for myself and friends. When I was 15 we moved again. My neighbor had a Fiat dragster and his friends all drove hot rods so I spent most of my free time volunteering to help with the Fiat. He raced on Sunday and after school Monday I would help disassemble the blown Hemi engine and wash each part in soapy water and dry them so he could inspect them for wear before reassembly. I wasn't allowed to assemble anything. The only way he could be sure it was right was if he did it himself.

Taking courses at nights is a good idea but to get some hands on experience I would suggest you get an old car that's headed for the junkyard and start taking it apart. Some people will give them away to get rid of them. The price of junk is up right now though so there are a lot of people competing for the junk. You might have to pay $50 for something to tinker on. Take apart the door and window mechanism. It can be quite a challenge to get them back into operating condition. Then try the carburetor, alternator and starter. Take off some body parts and put them back. If you run into problems just ask here and someone might be able to help. A few auto repair manuals will also be a great help. If you can't put something back together just toss it in the trunk and start on something else. If you plan to junk the car when you're done then you don't have to worry about screwing something up beyond repair.

Think about getting a job in a body shop or a new car dealer and you can learn from your co-workers.