One of the things that has worked from early childhood to higher education is my discussion on Respect & Choice. The first day I let them know that RESPECT for self, others, rules, and things around them is imperative. This includes communication. No one is entitled to respect. It is earned. Second, CHOICE is the ONLY thing in life you truly ever own. No one chooses to be born or to die but the choices we make from beginning to end are solely our responsibility and we are responsible for all our choices; good or bad - right or wrong.
Those questioning everything seem to be choosing to challenge you, not the work. Questions: How stern are you with your class management? Have you taken the ring leaders off to the side and asked them what is really going on? In my experience, adult education classes are a lot like a work environment. Employees & management. If the management isn’t solid the employees tend to run things. Just a suggestion, look at Blooms Taxonomy. https://cft.vanderbilt.edu/guides-sub-pages/blooms-taxonomy/
These concepts work in both teaching and class management. The point is; whether primary/secondary/higher ed -- especially those who came from Low SES (maybe even went to alternative schools); stay firm with the school protocol, school rules, curriculum, and class rules. Those who question are curious. Those who challenge are merely pushing your buttons. You can choose to allow them to continue (and get under your skin) or you choose not to, and put down your foot.
However, keep in mind that humor along with the sternness is a great recipe.
Trust me. It works. I’ve had many successes with this, including helping gang members out of alternative school to graduate into higher education -- and graduated. ;-)
Good luck
