And if at first your wrists and hands hurt. You can keep a secure grip but keep your hands loose if you drum your fingers every five minutes or so. Cycling is a relatively easy sport. There's no pounding or twisting, but a common beginner's mistake is doing too much, too soon. To get the best workout, watch your pedal cadence.
Most people go too slow.
Ideally you should pedal at 90-100 rpm. As a beginner aim for 70 rpm. That's about one pedal stroke a second but don't spend your whole ride counting. It's a toy as well as an exercise machine. Some 20-mile rides, a little bit shorter, a little bit longer.