Barring any medical conditions you have that might make exercise difficult or detrimental, I would say there is no problem with you getting back into shape. Just do not start out at too high of a level. Work your way up slowly with aerobic and weight training. Perhaps starting out with just walking and increasing your distance would be a good way to begin.
I would seek advice from a nutrition counselor and maybe even a personal trainer. You are at an age where you would be able to get yourself in peak physical condition.
Think of it like playing the piano. If you have not done it since childhood, it takes time to get back into the swing of things and continue on but you must practice, practice, practice.
My best wishes for you in your success.