Overweight and Over 50

That should be a beautiful ride, Laura.  The best thing to do to start is ride, ride, ride.  But if your just starting out in cycling you need to build your strength.  Get in lots of base miles to start.  Watch your diet.  You need to eat to ride, but cut out any over processed sugary stuff.  Eat fresh and keep yourself hydrated.

Kelli

Before you log the miles - make sure your bike fits you.  Many riders begin or return to cycling on a bike that does not fit or worse yet a loaner or hand me down that doesn’t even come close to fitting.  If you don’t have a regular bike shop, seek out one that is willing to fit you to your bike, whether new or old.  Pick a weekday and make an appointment. A good shop will be willing to take the time to fit you and find the parts to fit your body and your budget.  Logging miles on a bike that just doesn’t fit you properly is uncomfortable at the least (and may drive you from the enjoyment of the sport) and can cause you injury at the worst.
As the season progresses and my winter weight drops away, I find I need to tweek my bikes to fit my changing body (New England winters are not kind to the waistline and other areas). I find I need to slightly change seat height and saddle position every three to four weeks as my fitness returns and my body changes shape. So be prepared to adjust the fit of your bike as your weight drops and your shape changes(and it will!).
Good luck!
Susan