For how long is the course? (Just out of curiosity, unfortunately my mom probably won't allow me to study abroad alone at this age:-[ )

Alice, the WSS program at UNC is a three semester program for required courses. It's only offered to students who get accepted into the University of North Carolina. But there are plenty of things you can do on your own. Check out this post: If you are a beginning screenwriter..., lots of resources and tips.