[GaltAdonis]

Learn what a condenser and points are.
Buy some appropriate ‘old tech’ tools.
Make a workspace in the garage.
Standardize on specific (relatively simple) older vehicle models, and buy a couple or a few.
Stock up on the routinely replaced parts for those vehicles. (filters, spark plugs, etc…)
Buy Haynes and Chilton’s manuals for those vehicles.
Get busy.

[GingisK]

I probably still have my timing light.

[Carry_Okie]

‘68 Dodge Power Wagon.

[Pollard]

Engines are easy enough. They need fuel/air and spark. Electronic transmissions are another issue.

The computers on many newer vehicle are fairly hackable. — https://www.hptuners.com/

There’s a PCM - Powertrain control module and then everything else are individual modules. Anti-lock brake module. Passenger restraint/airbag module. Anti-theft module. All of those sub-modules can be turned off in the PCM.

The Chevy LS series engines, 4.8, 5.3, 6.0 liter can be brought down to a single wide band O2 sensor, injector and spark control. Transmission control can pretty much left alone but shift point are often adjusted. Many people are transplanting the LS engines/trannies into 1950s - 1980s vehicles.

The newer V8s get 20 mpg instead of the old carb engines getting 7-10 mpg and easy cold starts is something I prefer.

[Disambiguator]

I’ve been doing those things for over 40 years. I have a timing light, tach/dwell meter, all the good stuff.

[brianl703]

Spend the extra money to get the factory shop manuals, they are worth it and, for older vehicles, can often be found cheaply on Ebay.