what will happen if your cell phone storage is full where it becomes hard to free up spaces and hard to clean up storage?

Delete as many photos and videos as possible. Delete apps you dont need. Then plug the phone into a computer, import all your photos/videos BOTH on the computer and on an extra flash drive, then delete more stuff from the phone.

Or get a bigger SD card.

Delete unused apps. Delete unnecessary files. Clean your cache.

it blows up