Doing push-ups or bench presses with dumbbells (be sure to weigh them or use barbells) is a very good way to practice pectoralis major.

It is advisable to have muscle aches every time. Remember not to do it every day. Every time you do anaerobic exercise, you should destroy your muscle tissue as much as possible, and then use enough time and nutrition to repair the damaged muscle tissue and let it grow. To put it bluntly, muscles grow out at rest after anaerobic exercise.

Only scientific fitness can have perfect muscles. (Original, don't copy)