Hi Elisabeth, the first thing u should know that u cannot work legally in Brazil, unless u leave ur country with a work permit, with a brazilian employer hiring you. But u can try something informal at a bar, night club or hostel. And unless u work in a hostel, u will need to speak portuguese or spanish cuz people dont speak english here. Good Luck! ;)
Well, Elisabeth, would be better for you try to find a job in touristic beaches during the high summer season, specially from Florianópolis to the north, because to the south its full of Argentinians, Uruguayans, etc, spanish-speakers in general. Anyway, you can find jobs in bars and cafes during the whole year, but must try in big cities as Curitiba, São Paulo, Rio de Janeiro, or small cities like Gramado, here in the south, places where they really need people who speaks english or any other language but portuguese. Here in the south we dont use to need it because isn't a place of much interest of foreingners.