Yoroshiku onegai shimasu and Hajimemashite are the same?

There is any diferenc between Nihon and Nipon?

I would like some one to teach me japanese! any one available? well I know portuguese, and a quite bit of spanish, English is not a problem for me I'm not so good as I would like but I can talk! if you can teach me japanese I try to teach you any of these languages ^^