I have been testing my form with submissions and I dont want my uploaded files to take up any of my 100MB of storage. Can you please clear it out ?

You can delete the test submissions with uploaded files in your My Forms View Submission page.

user guide: How-to-view-Submissions

Please take note that deleted submission data are permanentely gone and cannot be restored. So make sure to know which submissions you are deleting and download a copy as well if you have plan to use them later.

Let us know if you need further assistance.