If you are under 18 I don't think you can have your own insurance policy. I had to be under my parents until I was majority age (18). This is because you have to be 18 to sign a contract and an insurance policy is a contract. Also you can't get insurance unless you have a license and a vehicle.
It depends on what part of the country you are in. I'd suggest going on Gieco or Progressive to get a quote. That way you will know immediately what you are looking at. Other companies should be around the same amount, give or take. You might get a better price if you are added to your parent's policy and you pay them. Good luck! I hope it's not too bad.
Yeah, for a kid just starting out these days, it's cheaper if you add on to your parents' policy. Even at that, it could be $1,000 a year or more. Usually it's paid every six months.
I have never known anyone who did this before, why are you trying? It is easier (and cheaper) to stay on your parents insurance. This is what most new drivers do in order to be able to save up (insurance is not always cheap).