How do I delete files from my Macbook Air M1 but NOT from icloud

Depending on the items you need to access from individual devices &/or Mac

there are things to consider in how to accomplish this. I was able to use iCloud

to allow an iPhone and alternately two Macs access; this changed each product

so those could not engage iCloud. ~ Those changed, were kept in their place(s.)

This is more difficult when various products using iCloud are of varying vintage.

You can do an end-run around the iCloud functions, by selectively setting their

preferences or settings; to isolate their status. iCloud will complain a bit. Let it.

iCloud does exactly what it was designed to do. It backs up any of the changes on your Mac. If you delete a file from your Mac, iCloud will do the same.

iCloud synchronizes files across devices accessing the account. If you delete a file on a device that action is synchronized across all devices. What you describe that you want to do will require an external drive on which you can store files to free up internal drive space.