The age to legally become emancipated from your parents in most states and jurisdictions is 16 years old.
Getting emancipated grants the teen the right to independence from their parents or guardians and then the teen is no longer obligated to do what there parents or guardians tell them to do.
So when you become emancipated you're basically on your own and your parents and guardians are no longer legally obligated to provide or care for you.
Being on your own is difficult and expensive so unless your parents or guardians are really bad then you should really stay with your parents for as long as you can.
Once you get out on your own and become emancipated the cost of living is all up to you along with all the other responsibilities that come with being an adult.