free tier- how does it work

Your usage as described isn't in-scope of Free Tier anyway, for which the only instance types are t2.micro and t3.micro.

You can view your current Free Tier entitlements at https://console.aws.amazon.com/billing/home#/freetier

If you have any IPv4 addresses associsted with the instance then you'll start being charged 0.5c/hr once your account exits Free Tier https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address-charge-public-ip-insights/

If your free tier for AWS services is expiring, you may incur charges for the services you are currently using once the free tier period ends. However, the specific impact on your costs depends on several factors:

Usage: If you continue using the same AWS resources and services beyond the free tier limits, you will be charged according to the standard pricing for those services. For example, if you are using a t3.large instance for your Windows image, you will be billed for the instance usage based on the on-demand pricing rates once your free tier expires.

You learn more about free tier here :- https://aws.amazon.com/free/free-tier-faqs/#:~:text=The%20Free%20Tier%20applies%20to,billed%20to%20your%20credit%20card.

https://repost.aws/knowledge-center/free-tier-expiring