How does becomming a ward of the state work?

I'm only 15, my mom wants me to move out. She said she is going to draw up papers giving me up to my dad. I've just met my dad within the last 3 years. I'm not comfortable living with him. Also he is an ex cocaine and god knows whatever else addict. He has been clean for awhile but is still not completely on his feet. I want to live on my own, I have a part time job and have found a place that I can afford. It would be tight but still workable. In the case that she refuses to give me up to the state out of her own stubborness would I be able to get the government to provide me with a lawyer to fight her in court. I'm just worried about legalities, due to the fact I am underage I don't know for sure if I would be able to rent an appartment. What does being a legal adult mean exactly. I'm against having to live in foster care when I am able to support myself. Another reason I want to be a legal adult is so that I can apply for welfare and live comfortably. Any answers or reccamendations would be appreciated, thanks.