This is definitely the “go-to” chest exercise. As there are many different ways to do this, lets review the basics. While laying on a flat bench, use a wide grip on the bar. Lower the bar to your upper chest/lower neck area. Repeat.
This exercise is diverse. Changing the grip and where the bar is lowered to changes the area of the muscle that is impacted (inner, outer, upper, lower). Also, using a decline or incline bench will effect different areas of the muscle.
Free weights can be used to imitate a number of machine and bar exercises. For example, I like to use dumbbells to do incline bench press. They work well for flies, which are a great exercise for stretching the muscle.
Parallel Bar Dips
This one is tough if you have never done it before. With hands placed at shoulders width apart, lower your and raise your body between a set of parallel bars. Widening the hands places more stress on the outer pecs and deltoids.
This is another classic yet super effective chest exercise. When you think about it, these simply imitate the bench press but use your bodyweight instead of a bar.