Congratulations on your class Janet.
Before I suggest a format or exercises, I think it might be a good idea to ask yourself:
1. What is the objective of the class?
2. Overtime, what training adaptations are trying to achieve for with the group?
3. What aspects of function will you be addressing as you teach the class?
4. What is your viewpoint of functional fitness/training.
Think about the above Janet and write your answers down. They will serve to be a good reference as you design your class.
As you look at your class, are you able to determine from the way that they move or from their static posture whether or not there are deficits in balance, flexibility and or strength? Those are all areas of function that we all can improve upon.
Too, you are likely aware that as we age we lose flexibility, balance and strength. Those three aspects of fitness might be areas you could consider including in your class as you prepare it. Any loss in those areas lead to movement inefficiency.
See if you can find articles on this site relating to functional efficiency, functional balance, functional strength and functional flexibility that might assist you in coming up with programming ideas for your class.
I wish you the best for your class.