There is such a thing as legal emancipation. You need to look it up on the internet and see if you are eligible. If you need more advice, I suggest you contact your school counselor, or call the youth services in your home town.
If you really don't want to be there, and it's an unhealthy environment, either physically er' mentally, see if you can get into a foster home, social services can help with that...it made my life amazing and I'm 15 too. The grass is truly greener on the other side..:)
Contact your school councelor or your local young peoples organisations. You can find out where your local youth organisation is from the internet.
First of all you should ask yourself why you want to do that. Secondly: Is it worth it? And thirdly: Is there anything Else I can do about it? Leaving home is not a decision to be taken lightly. Whatever your problem is, you need to try and solve it, not to run away from it.
If you have good arguments ( like violence) go to someone close and stay there. But if you want to leave home because you had a fight with your mom and dad this is not the solution! It's better if you talk with them. Trust me! This kind of opend discussions can resolve problems!
I will do that.. I have just left my 19th school so will have to wait until the new year until nI start my new school! THanks!! :)