Not going to happen. First, Maryland does not have a statute on emancipation. Therefore, even with parental consent, it will not happen. And if it could, you would have to have the means to live on your own, not rely on living with someone else. However, you will be considered emancipated when you turn 18. So all you need to do is wait until then.
If your parents are OK with it, you can look into having the other family gain custody of you. Your parent and them should consult a lawyer on how to have this happen.
Q: "At what age is an individual considered emancipated? Can I petition a court to become emancipated?"
A: Article 1, 1 24, of the Maryland Annotated Code provides that the age of majority is 18, and that a person reaching that age is an adult for all purposes, except when specifically provided otherwise by statute. Unlike some other states (like California), Maryland does not have a youth emancipation act. There are some instances in which a Maryland youth may become emancipated. For example, § 2-301 of the Family Law Article permits the emancipation of a minor by marriage. That means that the child is freed from the control of the parents, and the parents are free from the duty to support the child. Emancipation by marriage does not free the child from the legal disabilities (voting, drinking, ability to enter into contracts, etc) imposed on minors unless a statute specifically says so. A minor who is married has the same capacity as an adult to consent to medical treatment or to hold title to property as a tenant by the entireties with a spouse who has reached the age of majority.