macOS Monterey Update

What did the error message say?

If you go to your Applications folder is there an app titled Install macOS Monterey? If so delete it.

Next try booting to Safe Mode. That boot up takes minutes and clears caches and other things that may resolve your problem.

How to use safe mode on your Mac - Apple Support

The wording of the question would indicate one is downloading an Update to Monterey which would mean there is Already an earlier version of Monterey already installed on this computer.

It that correct ??

Or, does one mean downloading an UpGRADE from what pervious version of macOS. ?? and If so what version?

Did you empty the trash after deleting the bunch of stuff? After reading these instructions about creating screenshots, could you upload a screenshot of About This Mac - Storage?