from when free-tier period counts?

The AWS Free Tier period begins on the date you activate your account, not when you create it or when you start using specific services. In your case, if you created your AWS console account about 7 years ago and activated it at that time, your Free Tier period would have expired long ago.

The Free Tier benefits last for 12 months from the account activation date, which requires adding a valid payment method, verifying your phone number, and choosing an AWS Support Plan. After this 12-month period, the Free Tier expires and cannot be extended, regardless of whether you used the services or not.

The "free-tier available" label you saw while creating the EC2 instance might be referring to the "Always Free" tier, which includes some services that remain free indefinitely, or it could be a short-term trial offer for specific instance types.

Given that your account is 7 years old, it's unlikely that you're currently eligible for the initial 12-month Free Tier benefits. To avoid unexpected charges, you should carefully monitor your usage and costs, especially for the EC2 instance you just created. If you're unsure about your current billing status, it's advisable to contact AWS Support for clarification on your account's specific situation.
Sources
Understand when AWS Free Tier starts and expires | AWS re:Post
Free Tier Extension Request | AWS re:Post
Avoiding unexpected charges after Free Tier - AWS Billing