Set up an appointment with the dean of students. Let him know that your 12-year-old child would like to start taking a course at his college. This should pique his interest when hearing that a child wants to go to college.
Have your child dress nice for the appointment and explain to the dean of students that your child is ready to take a college course. Tell him that your 12-year-old would like to start out taking one course and gradually take more courses until eventually he has a full load.
After receiving the dean's approval and signature, sign up for the chosen course that the 12-year-old would like to take. You can choose a campus course or one that is online. It may be wiser because of your child’s age to choose a course that is offered online. Either one will give him credit towards his college degree.