You need to return the Economic Stimulus Payment that you should have not received since you were not eligible.
Go to this IRS website for how to return the payment - https://www.irs.gov/newsroom/economic-impact-payment-information-center-returning-the-economic-impac...
You were not supposed to receive a stimulus check. At your age you can be claimed as a dependent and should have indicated as such on your own tax return. You made a mistake very common for teenagers and students filing tax returns for the first time by not saying on your own return that you can be claimed as someone else's dependent.
Unfortunately for your parents, when they try to e-file their own return, it will be rejected because you filed incorrectly and said you could not be claimed. So you should alert them to that now. They will have to print, sign and mail their own tax return that claims you as a dependent. They cannot e-file this year. (even if you amend your return.)
As for the check you received: