How would you do it like step by step?

You cannot put yourself into foster care.

Report your parents to child protective services for child abuse. Once that is done they will come and investigate. If abuse exists, the will have your parents arrested and you will be placed in foster care.

There is only 1 step. Report the abuse being imposed on you by your parents and/or guardian to your local Family Services agency. They will investigate and, MAYBE (though unlikely) they will remove you from your home and place you in foster care.

I'm not sure where you get the idea that foster care will be better than your current situation. Odds are it won't be.

How old are you and why do you want foster parents?

I agree with others, you can not put yourself in.

You can report the abuse or neglect of parent or guardian and they will investigate and take proper actoin