It is insulting to call Brazilians Spanish-Americans because there decendents are from Portugal and they are proud of their heritage. If you are visiting Brazil from the United States, please do not say you are from America. Brazilians find it offensive because, after all, they live in America, too! Say you're from the United States. .
Rio de Janeiro is pretty casual and things move slowly. Sao Paulo is quite formal and tardiness is considered inconsiderate. If you are planning to attend a business meeting there, you might want to take along a conservative dark suit or dress.
A meeting in Brazil begins by shaking hands and exchanging business cards. When introduced to someone you call them by their first name but first say Senhor, Senhora or Senhorita (Mr., Mrs. or Miss), as in Senhorita Maria. Last names aren't usually used. Women in Brazil often say hello with an "air kiss," which is just barely touching opposite cheeks.