Push-ups, pull-ups, sit-ups and squats can already exercise a lot of muscles. If you want to be more perfect, you should also practice arch bridge, which is to exercise your back muscles, but it is actually very useful.

Push-ups practice triceps brachii (upper arm muscles push), deltoid muscles (shoulders), chest muscles and core areas (that is, abdominal muscles and back muscles). When doing it, the wider hand spacing emphasizes the pectoral muscles, the narrower hand spacing emphasizes the triceps, the foot pad emphasizes the shoulders, and the fist pressure and finger pressure emphasize the forearm. Push-ups are the most important movement. Even if you only do push-ups, your upper body muscles are already in good shape.

Pull-ups of biceps brachii (upper arm muscle for pulling) and latissimus dorsi (muscle between arm and side) greatly improve arm wrestling.

You can also bend with dumbbells, which can approximately replace pull-ups To be clear, you can bend your arm and let the dumbbell move up and down.

Sit-ups should be needless to say. . .

Squat is squatting to stand up. The greater the range of action, the better the effect. When squatting, it is best to control the forward distance of the knees not to exceed the toes. This is as good as possible.

All right, I'll try to answer the rest.