Closing All Resources

Check your Free Tier usage to see what you are currently getting for free, but may soon be charged for https://console.aws.amazon.com/billing/home#/freetier

Detailed advice on terminating resources you don't need any more is here https://repost.aws/knowledge-center/terminate-resources-account-closure

A drastic option if you want to terminate all running resources is AWS Nuke (caution: use with care!) https://docs.aws.amazon.com/prescriptive-guidance/latest/patterns/automate-deletion-of-aws-resources-by-using-aws-nuke.html

Hello.

I think it's a good idea to follow the steps in the document below to find if there are any active resources in your AWS account.
I think it is easy to search for resources using the tag editor described in "Confirm you have terminated all active resources".
https://repost.aws/knowledge-center/check-for-active-resources