submission storage

It appears you accidentally posted an empty thread. Since you titled your post as "submission storage" I'll just give you a general answer on what that means.

For the free plan, the total submission storage is 500. This is the total (and not monthly) meaning, once you reach 500 or more submissions, your account will be over limit and will be bound to be disabled unless you upgrade. You can delete submissions though if needed but keep in mind that this is irreversible and your deleted submissions can not be restored.

Related guide: How-to-Delete-Form-Submission-Data 

Currently, you just have 7 submissions so far so you still have a long way to go before hitting the limit. Monthly submission limit for the free plan on the other hand, is 100. You can find all the limits per plan on this page https://www.jotform.com/pricing 

Let us know if you have further questions.