What is a foster home like?

I hate living with my mom I absolutely hate her and I wanted to try to get a legal settlement to let me live with my grandparents but it's hard and I found out they don't like me and want me in military school so they don't have to pay for me so if I try to get in a foster home to get away from her what would it be like. Also does anyone have any ideas about different things to do besides this and also I'm 12