LEARN PORTUGUESE IN BRAZIL
If you really want to understand the people (literally and also from a cultural point of view) then it is best to learn the language. Now, whilst Spanish maybe more widely spoken in South America it is not that difficult to learn Portuguese, especially if you already know a Latin language (such as Italian or Spanish). You'll probably find yourself wanting to come back to Brazil, so it would be a good idea to invest some time in a Portuguese course.
If you decide to spend some time in Brazil, it would be very worthwhile to make your stay more enjoyable and learn the local language – Portuguese. You can’t spend your whole day at the beach and it would make doing everyday things like going to the shops or requesting information from someone in the street so much easier if you are learning the local language. All the major cities in Brazil like Rio de Janeiro, Sao Paulo, Salvador etc. should offer Portuguese courses for foreigners. Some well known schools including Britannia and IBEU offer English courses for Brazilians as well as Portuguese courses for foreigners.
A basic Brazilian Portuguese Lesson