How do I to turn off file sharing from my MacBook Pro and my new MacBook Air? Both are running Sonoma.

I want to separate the desktop files from the new MacBook Air. iCloud has sent all the files across to the new computer, and I really only want a few work-related files on the MacBook Air. Would appreciate a step by step instructions for this. Also, when I do disable file sharing - and I delete the files that have already come across from the old MacBook Pro on the MacBook Air, will this stop them from being deleted on the MacBook Pro also?