Ramon, like in all countries, the choice of terms to address people is not always a clearcut thing. We use "o senhor" or "a senhora" very frequently in Brazil. At home, for instance, there are people who address their parents in these terms. I don't, but I used to call my grandmother that. It depends a lot on the internal culture of the family. In non-domestic contexts, like at work, you assume it is appropriate to address those above you at the corporate ladder with "o senhor" or "a senhora", unless they tell you not to. There may be tricky situations, like when the boss is much younger than the enployee, and often the boss tells the emplyee not to bother. On the street, you address an elderly person, for example, normally with "o senhor" or "a senhora". Very often they tell you not to bother, so then you may drop it. This is my rule of thumb: if in doubt, use it. If your interlocutor does not care about it, they will normally tell you not to bother. Hope to have helped you and wish you all the best with your studies of Portuguese.

Hello Ramon. To use "senhor" or "senhora" is very common in Brazil. Mainly at north, people use to call their parents (and grandparents, uncles etc) of "senhor/senhora", but this is common in other regions too. Example: "Mãe, a senhora vai fazer brigadeiro hoje?" In all regions the terms "senhor/senhora" are very common to use with customers at restaurants, shops etc. Example: "O senhor gostaria de batatas extras?" Also, as in Brazil we use "você" with a different context from Portugal, "senhor/senhora" are the most used when we need to use a formal or even a semi-formal term like when we talk to older people, officers, bosses etc.

Here in Brazil this is more used to formal things, like in companies, banks whatever. But, when we don't know someone and we need to talk to them we use "Senhor or senhora" as a sign of respect. Mostly for people that seems to be over thirty. Over this age is a lot more used "Moça and moço". Understand? Hope I can help you.

In Brazil,we use Senhor e senhora too

Ramon no Brasil o uso dos pronomes de tratamento ocorrem frequentemente por exemplo: O Senhor José chegou tarde para o almoço. A Senhora precisa de ajuda? Mas é um uso formal.