DON’T speak Spanglish.
Do not think is cute to insert a few words from the Spanish lessons that you may still remember. It is condescending. Stick to a clear, no slang, Good English. This does not mean that you should be shy to say “Gracias” “Por favor” etc. the usual pleasantries.
In Brazil, no matter what, DON’T say a word in Spanish. Stick to English.Brazilians do not appreciate foreigners coming to Brazil and speaking a few Spanish words.