Got a new computer (imac with catalina). successfully migrated data. during set-up I mistakenly chose to have dropbox back-up my entire mac hard drive and this put me over my allowed storage limits. So I paused dropbox "SYNC" and went into the dropbox website and deleted many files and I am now within my storage limits but I do NOT want to resume sync because I cannot seem to remove or delete "My MAC" from the "All Files". Would appreciate any suggestions. Thank you.
If you've deleted the files in the 'My Mac' folder, then the moment you resume syncing, those files will be deleted from your computer.
Could you first try disabling the computer backup from Dropbox using the steps in this article? Afterwards, you can move the folders and files back to their previous locations, which will also delete them from the Dropbox account online.
If there are any deleted files, try recovering them from the Dropbox site.