I am 56 and have been cycling on a road bike for several years now. For years I rode my old mountain bike and it did everything I needed it to do. But it was heavier. Still, it got me back in the saddle.
My only thoughts are find and make friends with your local bike store. Your bike has had a maintenance check. Make sure it fits your body. Bikes can aggravate knees, too, so learn how to use your gears.
My motto is to see how much I can improve compared to myself. Cycling is a great way to challenge yourself and I find it exhilarating; hopefully you will too.
2011 Trek Madone 4.5 WSD
2011 Trek FX7.2--What can I say? It was on sale!