What seems to have derailed this thread is the disconnect between the OP asking specifically about "how to set up a militia rifle squad" but people mostly arguing about the bigger-picture questions of "does the militia need rifle squads" (and ultimately "what is a militia for and how should it be structured and used").
Starting with the militia's purpose/mission, how about "to protect their fellow citizens against enemies foreign and domestic, and to preserve or restore the Constitutional order of our Republic"?
However, in order to show presence and demonstrate utility in "peacetime", as well as for team building and training purposes, the militia could as well help with traffic control, search & rescue, emergency preparedness training for citizens, etc. etc. (understanding that these activities should not detract from preparing for their primary mission, and also understanding that those who are "out and proud" about being in their local militia will likely be among the first to be rolled up should TSHTF - so maybe in addition to the "official/open" militia there should also be a clandestine organization? But, during peacetime, that would probably draw a lot of attention from the powers-that-be, and may even be illegal in some states.)
In any case, that means "the militia" as a whole (and, ideally, every single squad/cell) needs to be able to cover missions on a spectrum from traffic control to search & rescue to intelligence gathering and analysis to propaganda to ambushes to raids on high-value targets to ... (depending on personnel, training and equipment), all in a decentralized, self-sustaining and potentially clandestine operational context. Thus, as someone else mentioned, for a "generic" militia cell/squad, the SF A-Team model is probably more appropriate as a building block than an infantry rifle squad. But hey, the OP wanted to hear about rifle squads
But the A-Team model also illustrates the challenge of finding the right people for it - "a hundred men we'll test today..."