Deciding what to put in the frame and what to leave out of the frame says who you are as a photographer. If you want an image that makes the viewer feel claustrophobic, you may want as much as you can possibly fit in the frame or have multiple things up close. On the other hand, you may want to make the audience calm, so having less action in the frame can translate that emotion. Having extra stuff in the frame can also distract from the main focus in an image. Deciding what is in the frame is everything when taking a photograph.
Making photos is a process of decisions, deciding what is in the frame and how to use compositional elements. Stay open to experiences that happen when you put a frame around the world.