Icloud drive

See the articles Find and delete files on your Mac - Apple Support

Manage your iCloud storage - Apple Support

Then check iCloud storage Check your iCloud storage on iCloud.com - Apple Support

Note : the primary Mac book is synced with other Macs ( signed in with same Apple ID and password on the same network ) , deleting documents / files from one Mac will delete from others as iCloud Drive and desktops and documents box is turned in them Add your Desktop and Documents files to iCloud Drive - Apple Support

Use iCloud Drive to store documents on your Mac and iOS devices - Apple Support

Delete files in iCloud Drive on iCloud.com - Apple Support

When a Mac and other apple devices are signed in with same Apple ID and password on the same network , if you open system preferences > iCloud and uncheck the box of iCloud Drive a pop up window appears , showing to keep a copy of documents , and remove from the Mac .

( a ) if you had clicked on keep a copy , they will be archived in home folder that can be viewed by clicking on finder in the dock , take cursor on top menu bar > Go > Home > your user name > iCloud Drive ( Archive ) .

With an iCloud online storage, you'd have to first make offline backups independent

of those shared online Cloud storage items; so their content does not vaporize when

their shared hosts self-destruct their fabrication.

The iCloud Drive exists mostly to share files; unless you keep buying more cloud-based

storage; it cannot be sustained. Study the factors behind this situation, and ask yourself

can you live with third party cloud based storage (google is an example) outside Apple.

Apple support database has plenty of information. I've used some to keep my iCloud use

at 2.7GB (of 5BG free) for three years. A few times it got really out of hand; had to almost

buy/rent iCloud storage; and compromise an already tenuous fiscal situation, too.