What a great adventure you are embarking on. Bless you for doing that.
I think you should start off your class with a comfortable environment and a small project would be "hexagons", something small, they can take with them, and bring back to their next visit with you. You could show them samples, books, pictures as well as teach them about some of the quilting tools, along with assembling a small project like potholders or something of that nature. Of course they could work in pairs, or as a group and make something a little larger ie., table runners, once they were comfortable with the environment, could progress to something larger, baby/children quilts. Having experienced you are a friendly, encouraging group, perhaps they will eagerly want to return. I trust this will go well for you and I applaud you for taking the time to share with the Afghan people.
Look forward to some of your experiences and pictures for same. Best of luck with this endeavour.
Please do not hesitate to PM me if I can be of any assistance with supplies, etc.