I am 69, 70 in October, and had back surgery in 2002. I just retired and got back on a bike, a very used Hybrid, loved the ride hated the constant repairs. Bought a Cannondale flat bar and made a change or two but love the freedom of getting out and riding. I ride alone but that is my choice as I am not into trying to keep up or beat anyone else, just have fun and improve over my last ride.
Our local Trek and Cannondale shop were more than willing to let me have a decent ride time so go and ask. Hope you find what you are looking for.
Frank.