I am thinking of making a forum for my WC class. I am not sure whether to start my own site in a freeforum or use this with a thread, any suggestions?

Are you a teacher?  I suppose it depends on what your motivation is for having such a discussion forum.  Will it be a place for student side questions, a place where students are required to post, or something else?  Also, would you want it restricted solely to students in the class?  If so, you might want it password-protected.And if you do use a free forum service somewhere, it will probably have advertisements on it that users will have to see.  If you have any specific questions about forums, I can try to help you out.