You are not exempt from paying income tax or from having tax withheld for Social Security and Medicare. Do not say on a W-4 that you are exempt.
If your earnings for 2025 are less than than $15, 750, then you will be able to get a refund of the amount that is in box 2 of your W-2 when you prepare a 2025 tax return in early 2026. You will not get back anything withheld for Social Security or Medicare.
And....at 16, you can be claimed as a dependent on someone else's tax return, so when you prepare your return for 2025, it will be important for you to say on your own tax return that you can be claimed as someone else's dependent.