One thing I always do is ask some questions of the class before I start. Sometimes the people who show up only want to hear, say, travel stories, or maybe they are really into the gear. In most cases you will probably find there is enough diversity that you are back to your lesson plan, but at least everyone knows why you are covering some topics they may not have an interest in.

The other thing people want is hands on. With cycling this creates difficulties because of liability and fit etc... You may not be able to have people ride a bike. But anything you can think of where they get to try something, like setting up a tent, etc... goes a long way.

Most "normal" people have a lot of resistance to various aspects of touring. "danger" of cycling, scruffiness, sleeping goodness knows where, bad weather, and general uncertainty. So anything you can do to relax them, will really help.