how i can be a samurai or a ninja?

Go to Japan if u want to be a samurai and to China if u want to be a NInja!

In order to become Samurai, you need to have the samurai sword, where can be bought at samurai "shops" in many places (try buy online at http://www.japaneseswords4samurai.com/ ), AND you need to learn to control your sword and use it in fight. It's impossible to learn all those thing by yourself so you must go to some DOJO near your house (dojo: a place where you learn martial arts like karate, taekwondo, Jijutsu, etc) and ask them if they teach samurai techniques (just don't try it at home)

On the other hand, become a ninja much harder than samurai. You have to learn for more than 20 years (23 years in average) to make your response become quicker. So quick that your response / reflex will be 4 time faster than snakes. Ninja lesson can't be found easily either. You have to go to Japan and ask the people in the villages if they know any place to learn ninja. (almost) all of them are in secret places like mountains, etc.

Anyway, why would you wan't to become a ninja/samurai? I do think they are cool,, but gun and rocket launcher are faster than samurai and shuriken combined together.

Samurai were equal to armies whereas ninjas were equal to special forces. So if you wan't to become a modern samurai/ninja, join army.

First take a martial arts class and see if you like it - then train for about 5 hours a day.

Watch The Last Samurai

first of all decide what is it that you want to be that is a samurai or a ninja

joelina is basically right. only you go to japan in both cases :))

then you have to find a Master, willing to train a gaijin... that translates as barbarian, and means you ;).

in case of ninjas, you have to find them at all in the first place... after all... they are supposed to be a SECRET order...

in any case... good luck.