[Mobile] Storage

Depending upon your subscription plan storage covers all programs. Check all these locations for any files that count towards your storage limit:

https://assets.adobe.com
- check also the deleted files section - files are permanently deleted after 30 days, so if you still have storage full messages you will need to manually delete the files in this area;
https://lightroom.adobe.com
https://documentcloud.adobe.com
https://express.adobe.com/sp/
https://new.express.adobe.com/
https://assets.adobe.com/mobilecreations
- in the Mobile Creations area also check Deleted items.

Here's the help article about cloud storage and what is included as you may use other parts of it e.g. Libraries or Lightroom, that you haven't mentioned here:
https://helpx.adobe.com/creative-cloud/kb/file-storage-quota.html