The other day my Dad told me that I was old enough to make a decision
You can ask him if he really thinks you're mature enough to make a decision yourself regarding baptism.
If he says yes, ask him if that means he would support you if no matter what mature decision you make?
Would he really accept it to be your decision?
Or does he think you're only mature enough to nod and do as he says? Does Jehovah force anyone? (Actually yes, but JWs maintain he doesn't;-)
Respectfully discuss this with him. Either he agrees you're mature enough to make your own decision no matter what, or not. In either case you shouldn't get baptised.