How do I turn off iCloud without losing anything on desktop or in documents?
I do not require cloud backup and want to turn it off but don't want to lose any data on my devices
For information about turning off iCloud Drive, see the following from: Add your Desktop and Documents files to iCloud Drive - Apple Support
What happens when you turn off iCloud Drive or sign out of iCloud
If you turn off iCloud Drive or sign out of iCloud, a new Desktop and Documents folder is created in your home folder. You also have the option to keep a local copy of your files that are in iCloud Drive. If you keep a local copy of your files in iCloud Drive, they're copied to a folder called iCloud Drive (Archive) in your home folder. You can move any files that were in your iCloud Desktop and Documents to your new local Desktop and Documents.
That same support article also has instructions for turning off Desktop and Documents while leaving iCloud Drive turned on.