Usually the format is a 'jump in' session, and/or a round the room rota. Might do what we did at Portaferry last week, and run Saturday night like a Folk Club, with people doing 'spots'.
I have vague dreams of getting a ceilidh band sorted out, and I may have a caller, but don't know about the space or inclination for dancing. Don't do it myself, they told me when I got my hips sorted out I'd be able to Morris dance, but thank god it hasn't happened yet!
Giok