Why am I being notified about reached storage limit?

Also, there is a notice regarding storage for our account? Please advise as to how we can correct these issues?

This is because you have currently 501 submissions stored in your account, there is a limit for free accounts and they can only store 500 submissions.

To resolve this, you will need to delete your oldest submissions, otherwise they will be deleted. 

You can also download all your data at the same time, forms as HTML, submitted data, uploaded files, here is a guide that will help you to do it, so you do not lose information. 

How-to-export-all-of-your-data-at-once

You can also upgrade your account to the storage plan so you will not need to delete your submissions and they will not be deleted automatically by our system.

Hope this helps.