Avoiding AWS charges by terminating instance?

Hello, I happened to create 2 instances of AWS vps, I created 1st one while ago, this one should be lifetime free, is that correct?

Anyways, I happened to create second one, without me knowing of that 1st one (dont ask me how -_-) and I was charged about 4$ last month. I was like woot?

If I terminate both since I am not sure which one is that free one and then create new one, can that new one be free again? Also If I terminate them, there is no way I can be charged sohehow, right?

Thank you very much, I am new to this and amazon has everything so complicated -_- I wrote to support, but no answer yet, thank you!

They charge you by the hour of runtime and you get 750 hours a month for free. 24×30=720, if you got 2 running you are using 48 hours per day and so on... it doesnt matter if you terminate them or not, you will need to pay for what you spent. You can turn off either of them and keep using the other one for free for a year.