My personal opinion Q, and this is me talking some real shit to you wich prolly dosn't happen often.

DON'T do Tae Kwon Doe

1) It's one of the lamest Martial Arts to do
2) It's not affective unless you're really good at it

Trust me...

I wouldn't do Karate either if I was you. I've personaly done karate for 2 years at 3 differant clubs, and I found that it's almost imposible to find a genuine club that's more interested in teaching you the martial arts then taking your money. Most clubs are like a big scam, give you a higher belt every week and charge 50$ everytime. Expensive but you'll be thinking "wow i'm doing so well" -_-

TRUST ME

You might wanna try Jujitsu, or if you're into more self defensive, Judo. Muay Thai is also a GREAT martial arts, violent too. Kickboxing is like Muay Thai but less voilent natured and more of a sport.

It depends really if you want to do this for fun and get serious at it? And do you want to do competition if you get good?

By the way, you can't say "how long will it take until I become good" because you're either good at it or you're not. It took me around 3 years to become the provincial champion in judo and that's what I consider good....

__________________