Daily Minimum Bodyweight Exercises

Every day that you're able, do the following, in addition to whatever other training you have planned for the day:

25 pushups

10 pullups

25 reverse lunges or walking lunges each leg (50 total)

Any set and rep scheme to get those numbers is perfectly fine.

This will cover your strength and even general hypertrophy bases pretty well.

Combine these with a more specific hypertrophy or strength program, and you'll have some serious gains. But, it will take some serious discipline to do it.

Alternatively, maybe you don't care much for pure strength or fancy muscles. Maybe you prefer spending more time doing endurance training or various forms of cardio. That's fine and dandy as well (albeit, not my cup of tea). 

The above daily minimum is enough to check the box of strength and hypertrophy training for you without spending a lot of time.