it is absolutely possible to learn at almost any age, as long as you are in reasonable shape. It'll be great fun and great for you, so go for it.
Just a semantics note: kung fu is not a martial art, it's a Chinese concept that has little to do with fighting. Wushu is the technical term for Chinese martial arts, but it is also now used for Chinese gymnastics, so martial artists tend to avoid it. Whatever you call them, it's important to be aware that any umbrella term is covering literally thousands of Chinese styles which are as different from each other as Karate is to Capoeira.