Under the laws of all states in this country you and your minor friends can legally file an application with your state's secretary of state to have a limited liability company and actually own one. The problem is that since you are minors, operating such on a day to day basis may not be practical because as minors any contract you enter into on behalf of your entity can be deemed voidable by you.Given this many people or companies may not want to do business with you until you or one of the others reach adulthood.