Rurouni is a loose term for a 'Wanderer' that is the term people use when they think of Rurouni Kenshin. It's a loose term, meaning it also means 'vagabond' or 'bum', like someone who has no money and wanders around poor and hungry all the time (obviously people just like the mysteriousness and niceness of the simple term 'Wanderer' If people though of Kenshin as a bum, he would be less popular) Kenshin represents what happened to many real samurai of the Meji era. They had no lords, and when swords were banned they had no skills they could use to hold jobs. Many of them became wanderers and bums because the only life they knew was the life of a samurai. Without that, they had no idea how to live and get money.
Also, his name is Kenshin Himura. Things are different in Japan, and far more formal. In America, we call each other by our first name ( yo, Nikk, what's up?) and when we meet someone in a formal sense, we give them a title and call them by their last name (Hello Mr. Strife) In Japan, however, they are more formal, so they usually add on a title and use last names in more situations than we would, and your last name used to hold more weight than your first name. So in Japan, you'd call someone by their last name first (Kenshin Himura would be called Himura Kenshin, and people who knew Kenshin but weren't close to him would call him Himura) Only when you really get to know someone and become friends do you call them by their first name in Japan.
ALSO Kenshin is not his real first name, but I don't want to spoil it, so if you care you can e-mail me or message me through Answers.