1. get an old banger with a conventional engine- not too many electronics
2. start cleaning the engine
3. lie under the car and clean from that side too.
4. using a manual identify the parts
5. fix or replace what needs fixing or replacing.
We learn by looking, by being aware. Cleaning something is a great way to start awareness. You notice all kinds of things you might miss otherwise. The obsession with cleaning things in the navy is due to this reason- a constant way of monitoring wear and tear and teaching young sailors about their ship.