Scott: The term "Militia" means--by law--all able-bodied men of any community. At the time of common usage, and later, Congressional action, "able-bodied" generally meant males between around 14 years, on up to about 45. I would assume (!) that now, this would include homo sapiens of the feminine persuasion.
So, if you're upright and breathing and healthy, you're already part of the Militia.
No governmental blessing, apparently, is needed to create a "Well-regulated Militia". Well-regulated merely means trained; it does not mean subject to rules and regulations. The language-usage has changed in the last 100 years as regards such words as "regulate".
My advice? First, find those who are in accord with you. Then, organize into a group. After you get acquainted and become mutually and generally in accord on issues, get into LOCAL politics.
Run for such positions as County Clerk, County Commissioner, Constable, Tax Assessor/Collector, and Sheriff. If you're in a small town, go for City Council or Mayor. Also, try to be on the Planning Commission or equivalent, and any Advisory Group you can find.
If you and 20 to 40 associates can each influence 20 to 40 voters, you wind up being the local power structure.
You then influence what sorts of industries do or don't come to your area. You then have some control over what efforts are made to help the homeless. (If you want more of something, subsidize it.) You can determine the effectiveness of any welfare agency, and whether or not checks get mailed on time. If checks regularly are are late, folks dependent on them tend to move away...You can determine what sorts of investigations get pursued by local LEOs, and what civil suits get expeditious treatment and what civil suits languish for years...
An organized militia can be a lot more than a bunch of guys in camo.
FWIW, Art