No, I'm (now) a lazy slob busy parent, but my wife was a PT in a gym for a while.

It turns out that squats, lunges, press ups, burpees, pullups, boxjumps, and jogging/sprinting are pretty much all an ordinary work out needs for most people. Kick it up a notch with free weights and a bar to do dead lifts, cleans, etc and to add weight to lunges and squats or depth to pushups if you want to body build.

Specialized equipment might be necessary if someone has an injury or are training for very specific purposes.

When I did work out I found that keeping a log was useful to log e.g. AMRAPs or speed for motivation and having lots of subtle variations of the base exercises e.g. free squats vs heavy/light goblet squats.