How to do push ups
The right way to do push ups is to ensure your back is flat, no dipping of the lower back or no butt up in the air. Straight. Flat.
One of the major differences between flat bench press and push ups is the core engagement. Bench press is an isolated routine and push up is a synergistic movement. It’s why weight training is relatively easier than body weight training because isolated movements don’t require a lot of coordination and synergistic moves. That doesn’t mean weight training is not good. Weight training is great to target those weakest link muscle groups that prevent a complete body weight synergistic move.
Practice must begin.