How do I delete documents from my iCloud

See the following from Manage your iCloud storage - Apple Support

On a Mac with macOS High Sierra or later, you can manage your iCloud Drive files from the iCloud Drive folder in Finder:

1. If you need to, turn on iCloud Drive on your Mac:
   1. Go to Apple menu > System Preferences and click iCloud.
   2. Sign in with your Apple ID.
   3. Turn on iCloud Drive. In Options, make sure that you select the apps or folders for the files you want to manage.
2. Open Finder and go to the iCloud Drive folder.
3. Drag an item to the Trash, or move it to a different folder on your Mac.
4. Open Trash, then right-click the files that you want to delete.
5. Choose Delete Immediately.

OneDrive and iCloud are two different cloud storage services. OneDrive is a Microsoft service and iCloud is an Apple service. It is possible to save Excel files to either.

If you are asking about OneDrive, one method is to use a browser (e.g., Safari) and log in to https://onedrive.live.com/ and from there you can select the file and either delete it or download it to your Mac.