What are your goals? What are your expectations? What are the expectations of your students?
Since you have only 6 hours of training, I'd recommend keeping discussion to a minimum. Don't tell, show. And better yet, don't show what you can do, show your students what they can do.
Common occurances from past experiences:
Most people who attend the beginner's course do not join the dojo.
Most people get bored with long discussions about anything (philosophy, history, ritual and technique), they are there in gi or sweatsuits and want to do things.
Most athletic people can grasp forward rolls quickly. Backward rolls take longer. Breakfalls are terrifying.
The beginner's group has diverse interests. It's not possible to meet everyone's expectations in a short period of time.
Best of luck,