We've got Consumer Cellular cell phone service for about six months and we're quite happy with it. We did not go through AARP as I don't like that outfit at all. Instead, we went directly to the CC website and signed up.
We were able to port over my wife's existing Samsung Galaxy 8+ to the CC service. I had to buy a new cell phone from them as my old Samsung Galaxy 4 was too old to work on their service. I ended up getting a Motorola Moto G7 Power phone, and it's a nice piece of kit with a large screen. Android based, it has all the features of any other good smart phone. IIRC, it cost me $140 new from Consumer Cellular. I could have saved ten bucks and bought a refurbished version of the same phone, but figured for that little difference I might as well buy new.
There were a few minor technical hiccups when we initially started our service, mostly related to porting over my wife's existing phone, but their service reps handled the issues quickly and efficiently via online chat.
Two lines of service and an optional roadside assistance service are costing us $56 a month. Your cost would likely be lower with just one line.