Hello,
Do you have OneDrive cloud icon on your taskbar? If so, can you click on it and then go to the gear icon to launch Settings.
Then go to Sync and backup tab > Manage backup folder.
Are the folders turned on here?
If they are, turn all of them off.
Restart the computer. This should prevent files in these folders from being uploaded. If you notice any files missing, you can download them from https://www.onedrive.com from browser. Then delete them from the cloud.