Answer is here:
Your parents residency is the starting basis. You have to prove otherwise:
Under NC statute G. S. 116-143 the legal residence of an individual's living parents or legal guardian is prima facie evidence of the individual's legal residence. This means that the legal residence of the applicant is considered the same as that of his or her living parent(s) or legal guardian. That prima facie evidence may be rebutted or reinforced by other evidence relative to the applicant's age and general circumstances. Generally speaking, for an applicant with out-of-state parents, the older the applicant and more independent the applicant is from his or her parents, the more likely it is for the applicant to be able to demonstrate domicile in North Carolina.
• establishment of domicile (legal residence) and physical presence in North Carolina for at least 12 months
• residence has been maintained for at least 12 continuous months prior to the start of the term
• intent to make North Carolina a permanent home of indefinite duration
• evidence supporting that one is not in the state solely for the purpose of attending an institution of higher education
• Living or not living in the home of one's parents
• Voter registration and voting
• Location of jury duty
• Registering, licensing, and maintaining a motor vehicle
• Driver's license or state ID card
• Location of permanent employment
• Filing of North Carolina state income tax return
• Places where one resides during periods between academic sessions
• Location of personal property
• Property tax assessment
• Ownership of residential real property that is one's primary residence (including maintenance and payment of expenses associated with the property)
• Place from which one graduated from high school
• Place of residence prior to enrollment in an institution of higher education
• Memberships in professional associations, unions, civic organizations, etc.
• Sources of one's financial support
• Citizenship or immigration status
If you are not living, working, taxed, voting in NC, you don't live there.
If you own a car, it must be registered and insured in NC.
They start with a presumption that your residence is your parents. At 18, you can apply to prove otherwise. At under 18, it is a tough path.
There is some reciprocity of lowered tuition agreements between NC and VA for some schools, but not fully in-state. It may only be at graduate level. They are very strict about those rules.
If your car is registered to you, the insurance policy is odd to allow it in your parents name at all. In the same residence, they might let you get away with it. If your car insurance is on your parents policy, that alone could be enough to deny you residency.