Kudos for getting back on bicycles, regardless of the brand, or cost of the one you ride. And, welcome to the 50+ Forum, too. Lots of us are returnees after health issues, of varying types, you'll have plenty of encouragement here.

The idea about finding a local club is a great one, you can check in with some of the LBS in your are for them, and for others that are looking for riding partners. I ride the roads, always have and I have no issues with traffic, just stay alert, and don't be shaky, or irregular in your actions. A mirror, like the Take-A-Look that clips on your glasses arm, is a good idea. I will not ride without mine, same for my wife. Also, some flashing front and rear lights are my personal choice, never ride without them. I probably annoy the other riders in events like a century, but its a habbit

Bill