I would like to know how to free up some of our upload space?

Hello, I would like to know how to free up some of our upload space? 

Yes, you can delete the submissions where you received uploaded files in order to free up space, this guide will help you doing so: https://www.jotform.com/help/377-How-to-Delete-Form-Submission-Data

You may also download the data before downloading it in order to avoid losing it, these guides will help you doing so: 

https://www.jotform.com/help/73-How-to-Download-Form-Submissions-as-Excel-CSV-PDF

https://www.jotform.com/help/356-How-to-Download-the-Submission-Files

https://www.jotform.com/help/374-How-to-Export-All-of-Your-Data-at-Once