Hi Bearwoman
It is always a bit scary doing your first fair but just relax, it will be fine and i am sure you will enjoy it. It's always tiring but good fun.
I always talk to people briefly explaining you obviously cant do a full treatment and ask them if there are any particular problems they they would like working on. I do a couple of minutes warm up (or Greet the Feet as my Tutor called it) Then I do spine, head, shoulders and solar plexus for relaxation and then anything they have mentioned specifically.
I don't know how long you've got but you can easily fit that into 15 mins. If you give yourself a 5 min gap in between, it gives you time to hand them a leaflet and explain how they would benefit from regular treatments or a course of treatment if appropriate, tidy the area, before the next person arrives.
Good luck, I am sure it will go well.
Jackie