If you are far enough and have done well enough to be franchising im surprised you havnt done your homework to know how to go about finding a franchise already.
Surely Local paper, Gumtree, Social Media, wforsale.com, shop windows etc etc.
My guess is that finding the first franchise is the hardest part as you need to sell what you can offer without proof of anything working or history of doing it before.
Good luck with it anyway, seems so many are doing it these days and doing well from it so it probably will work with enough time and management put in.