Can I switch from Paid to Free?

I don't normally use a lot of entries but did this month because I started a 1 time project. If I pay to upgrade for one month, can I then cancel and go back to free without loosing the forms I have already created or my account?

Yes, you can upgrade and downgrade the account at any time. Your forms and data will not be lost when you downgrade.

You just need to cross-check your account usage limits before you downgrade, because, if the limits exceed that of a free account, your account will get disabled (data and forms will remain secure though - but users will see an over quota message on your forms).

You may want to check this guide on how account limits function: https://www.jotform.com/help/408-understanding-your-account-usage-and-limits

Do review and let us know if you have any further questions.