Nope, not too late. I joined tae kwon doe a while back, and there were plenty of people that were 30+.
Should I start karate? I am 17 and I was wondering if it would be too late for me to start karate. I am going off to college soon and I wanted to learn some kind of self-defense.
Try some Jiu Jit-su instead. For more contact do boxing. Kick-boxing, or Muay Thai.