Virginia Driver License?

Hey everyone I got my Virginia's drivers license a few months ago and I need help. So im 17 and because im under 18 i have certain limitations wen driving. Now it says that i cant drive b/w the hours of 12am and 4 am on the highways of the Commonwealth. Except to and from work or school/ case of an emergency/ when accompanied by a parent or person in loco paentis, or by a spouse who is 18 years or older. Now im wondering when it says the highways of the commonwealth does it mean actuall highways or all roads. and can i have a friend who is 19 drive with me?