About the already exported videos. Yes, if you have exported them you can use them and they will be available since you have downloaded them. However, they will expire in Minvo after x amount of days, which means you won't be able to edit them.

When you create and export shorts during your 7-day free trial, those shorts will remain available to the people you've shared them with, even after you cancel your subscription. The cancellation only affects your ability to create new content using our platform, not the availability of content you've already created and shared.

Minvo is a paid service, you can only export videos once you pay.
The minutes you are seeing are upload minutes.
We offer a 7-day free trial, so you won't be charged for the first week once you start on a Minvo paid plan.