Finder unresponsive - One move of a file might work. Otherwise get the rotating ball!

Does this occur for a different user, e.g., Guest? How to test an issue in another user account on your Mac.

Does this occur after starting up in Safe Mode?

Consider the possibility of a third party software conflict.  EtreCheck can be used to investigate what is installed.  You can post the report here.

The symptom you describe is consistent with startup disk failure.

Back up your Mac if you have not done so already. To learn how to use Time Machine please read Back up your files with Time Machine on Mac.