I would like to have some information about the free plan and how the limits are reset.

The limits on the free plan will reset each month (EST). There are only certain limits that do not reset such as the file uploads and total of submissions stored in your account. 

I would recommend you to check this guide that will help understanding the limits: https://www.jotform.com/help/408-Understanding-Your-Account-Usage-and-Limits 

If you have questions, let us know.