It all really really depends on your teacher and how they run the class (I'm sure the teacher you are thinking about taking from would not mind if you sat in on a class before you register). In my first college philosophy class, we were assigned readings and then we sat in a circle and had open discussion about it for the whole class period. It was a small class and everyone was really into it, so we had some awesome discussions (the teacher contributed to enhance our conversations, and if we got off track would steer us back). I thought it was an awesome class; very challenging, but in such a great way.
However, some teachers do not like the open discussion thing. There are so many different teaching methods that the teacher can use. Your teacher will have their individual style and methods of teaching it, and it will work for you or it won't (or kinda, haha). It also depends on which philosophers/philosophies the class concentrates on. Also, there are subdivisions you can take depending on your interests such as moral philosophy, epistemological philosophy, theological philosophy, scientific philosophy, economic philosophy, social philosophy, and the list goes on and on and on.
The best thing to do is meet the teacher, find out what other students think of that teacher, and if possible, sit in on a class if you are still unsure.
So yeah, I loved that class since I had a great teacher and great classmates, and I'm always up for a good challenge.