free up space on my iPad?

There is information in the following that may help: About storage on your device and in iCloud - Apple Support

Yes.

If you are able to locally stored data to iCloud, this may free-up local storage. You should be aware, however, that some iCloud documents used by your device may still retain a “local” cached copy for use whilst you don’t have an internet connection. Other documents or data may not keep cached copies unless they are being actively accessed and used.

One significant method of improving available storage on your iPad is to use iCloud for storage of your photos. When doing so, your full resolution images are kept in your iCloud storage - whilst a lower resolution version is retained on your device.