dear pinkcrystal -- I don't think anyone is ever too old to be in the gym. You might not be able to do elite level tricks, but you'll have lots of fun. I think with proper conditioning, flexibilty and strength training, and lots of repititions..... there shouldn't be a problem. Take it slow; have fun. Most gyms have "open gym" at least once a week. My gym also has Adult Open Gym. (strictly for those 18 and over). And we also have some adult classes. I'd say go for it.
Go for it! It will go great if you also do othe things that include stretching and conditioning, such as pilates, yoga, weights. I am a 48 year old granny and can do back handsprings, aerials, all-around--it is not like when I was young, though---takes longer to stretch out, and I have to pay close attention to my body.