Can someone teach me Mandarin?

I'm a fifteen years-old Brazilian looking for your help. xD

I don't know too much about it, but I'd like to learn 'Standard Chinese', which I think is coming from Beijing and written with western characters.

I just wanna learn the basic, as well as 'hi', 'hello', 'how are you?', simple answers and these stuff.

I'm also learning English and we can contact in this language, except if you speak Portuguese too xD

Thanks mates.