When I started, I was still in high school with. I didn't have a clue on how cars worked or how to fix this and that. I bought my own set of tools and then started doing basic maintenance on my parents cars like oil changes and minor tune-ups. Of course I've never done this type of stuff before so I did some research and just followed instructions. It was pretty straight forward but you do get to use your hands which is good.
After a while I started looking at the engine in more detail as in where is the head, block, oil pan, intake side, exhaust side...etc. etc...and I just think my way through. So I got more confidence to do more stuff as time passed since I had been doing alot of electrical and mechanical repairs and through that, I gained alot of insight on this stuff.
I also bought a motor for really cheap to rebuild. I got it for $100 so it was pretty cheap. I just look in the service manual for specs and just kept thinking my way through things. In the end I'm pretty satisfied where I am at right now..of course there's alot for me to learn but I do feel confident enough that I don't ever really need a mechanic anymore...except for some jobs that I dont' want to buy a tool for like pressing out wheel bearings.

get your hands dirty and do whatever you can...as someone suggested..be the tool monkey!

 

Here is the best I can tell you take it for what its worth. I started out working on cars when I was 13. I toke a bonch of shit apart and then figured out how to put it back together. I also had a older freind of mine and my dad were both tech. ( so hanging out with some body that works on cars alot can help , watch them.) I Now own My own business ( Hybrid-Garage ) I went to school for it, long after I was a tech at the local acura dealer . The school is only going to get you so far I did it only for the paper trail, better pay and the diag training. The Idea you had about getting a old better car and working on that is a great idea. That is the best way your going to learn. some body telling you how is only going to get you so far, hands on and setting down and working on it with your hands is the best way to learn it.