food is ubiquitous in carioca culture, and restaurant entertainment is generally more common than being invited to someone's home.  

however, if being received in a carioca's home, it is polite to bring a small gift to the host, and send flowers the next day with a thank-you note - the colors black and purple are to be avoided, as these are associated with funerals and mourning - violets maybe okay if they seem to be the right type to send.

at this point in the deal, introductions and formalities are long gone, and relaxed conversation commences - good conversation topics might include music, family, and the natural beauty of rio.