Welcome, Donna!
You've come to a good place for tips and inspiration, and advice. You've made a good start at caring for your health and fitness by riding a bike.
You'll get all kinds of advice, some answers conflicting with other answers, but in the end it comes down to your choices. Like you, I got into riding a bike to maintain my health and fitness, four years ago. I'm retired and living in Florida so I have plenty of time, all the year around, to go riding. I'm 72 so I don't ride great distances, usually riding 4 miles in the morning, 4 at lunchtime and four in the evening. Every few weeks I'll do a 20 - 30 mile run. In two years, riding two different bikes, I've ridden 9,000 miles.
Enjoy your rides and keep us informed of your adventures.