How can I recover my deleted files from iCloud?

Deleting files on iCloud Drive will remove them from all devices. Using iCloud is for syncing the same data across all devices signed into your account, so all changes will be reflected everywhere. You do not need to store your files in iCloud Drive if you do not want them available on another device and can always choose to store them only locally so they never take up any of your iCloud storage space. You can shut off iCloud Drive at  > System Settings > [name on top] > iCloud > Drive, and turn off iCloud Drive. There will then be an option to store those files locally or delete them.

For recovery, follow the link provided by 6x6, where all files are recoverable for 30 days after they have been deleted if they have also not been removed from the Recently Deleted folder.

You should be able to recover your files on iCloud.com: Recover deleted files on iCloud.com - Apple Support.