Hi, Anna. This is Paul Losch, one of the librarians in the Latin American Collection. If you're in the "Peoples of Brazil" course, you may have visited us last month.
I assume that you were told specifically to find a journal article, and not a book. I'll also assume that you want something in English, but, of course, there's lots more in Portuguese on Brazil than there is in English.
A good place to start online would be the Anthropology Plus database.
Go to www.uflib.ufl.edu/lac
Click on Databases(at the top)
Search for Anthropology Plus, and follow the link
You can also try, from www.uflib.ufl.edu/lac , the HAPI database. You can limit your search to English-language articles, if need be.
Using words like "Brazil folklore" and "Brazil superstitions" you should get a variety of results to choose from.
Sometimes these databases will give you links to articles that are online. Sometimes you'll get a citation, and then have to find out how to see the journal. E-mail me at plosch@uflib.ufl.edu , and I'll be glad to help you if you get stuck in that process. You can also call us at 273-2745.