Hi John - - When I was volunteering for different capacities through the AARP state office, which is 100 miles away from the rural community I live in, they kept referring me to a 'local' chapter that was 2 counties away from mine and encouraging me to start my own chapter, since there were several counties in my area of the state that did not have local chapters. I never looked into all the criteria needed to start a local chapter, but I would think you might need a minimum number of people to be members, have monthly meetings, establish a line of communication with the state office so you could do joint efforts, forward them the correct paperwork, etc.
If I was you I'd use this AARP website to find the best way to contact the your state office, and go from there.
Thank you for all of the information you provided. I am currently in Massachusetts but thinking of relocating to Florida in the upcoming years and up been looking in The Villages, but there is no chapter nearby. This is where I see an opportunity with a population of over a hundred and thirty thousand people in the AARP range..
I will contact the Florida state headquarters and go from there.