I'm making a couple assumptions here, but I'm guessing a granny patchwork quilt is one made with only squares, and that the women in his church group have been quilting for 20-30 years.
Dale, you can certainly do it. I think it's great that you are starting to quilt at your age, the same age at which I started. I'm 80 now and have made over 100 quilts. Good luck on your new adventure.