Be prepared to eat rice and beans every day, but also Sao Paulo is a massive city. There are people all over the street, all the time, crazy drivers, lots of buildings, houses stacked on top of each other. Just be prepared to see a lot of people in a very small area.
I cannot stress enough that there will be so many street dogs with mange and all kinds of fleas. Don't get close to them. Don't touch them. You won't want to. But there's a lot of loose street dogs. Be grateful every day that we have animal control and the pound here in the United States. And yeah, there's some wild dogs out there you want to avoid.
It's pretty poor. I would realize that before you go out there. I only had one area where there were people with, you know, some money. Try to blend in as much as possible. People appreciate that, you know, nobody likes to show off, especially when people don't have money or means or things like that. Avoid talking about a big house.