Just. Have. Fun. That's the key. The more you have, the more you'll ride. If you'd like something structured to help you get back into the sport, "The Time Crunched Cyclist" is a great book.
Putting an event on the calendar is always helpful. Take a look to see if there are any metric centuries near you to target.
Al Painter, NASM CES
Never attempt any new exercises mentioned in the fitness forum without a thorough evaluation from a physician, personal trainer, strength coach, athletic trainer, physical therapist or sports chiropractor. To do so without their consent, is to do them at your own risk. Riders/racers at the high school level must obtain written parental consent to request training advice via direct message.