About the free AWS quota

I would like to ask you something about the 12-month free quota when I created an account on AWS.

When I searched AWS to use NVIDIA's DIGITS, I found that NVIDIA had a set that could use DIGITS.
https://aws.amazon.com/marketplace/pp/B01LZN28VD

I was going to use this, but I understand that the total cost of using AWS is the amount that I pay for 1. instance price, 2. storage price, and 3. data volume.
When I created an AWS account, I understand that instance prices are covered because the usage limit was within 750H, but how do I handle free storage and data volume billing?
Is there a storage limit in the free space?

I'm sorry if my original understanding is wrong, but I appreciate your cooperation.