You are never too old to start exercising. I started at 42! After High School I threw out my sneakers. Yay! No more gym classes. For 25 years I didn't even own a pair of sneakers. Never heard of Nike or Adidas. It was a close call to death that made me change my mind about exercise. I didn't work out with a professional and made many mistakes along the way. Here are some helpful hints that I picked up over the years. You can borrow DVD's from your local library and see what appeals to you. The internet is a great source of information. Or, find someone whose physique you admire and ask them what type of exercises they do. I'm sure they will be happy to tell you and maybe even show you a few.
You don't have to spend money on a gym membership. Walk, run, climb stairs or you can do old school, pushups, jumping jacks, jump rope, squats, lunges. Find something you love to do and it wont feel like exercise.
As always, please check with your doctor before starting an exercise program.