My first car was a 1989 Mazda 323. I did minor things like plug wires, changing snow tires, bulbs, and one oil change.
But my first beater, bought with my own money, was a 1982 Cadillac Cimarron. And it was the first car I really worked on-- including diagnosing. Complete tune-up, vacuum lines, oil changes, rust repair. What an awful car! I eventually figured out that the Wells brand distributor cap and rotor were hot garbage with their aluminum contacts, and switched to something with brass parts. Upped my top speed from 55 to 75 MPH.