arrived in: São Paulo
We used Uber quite a bit (including to/from the airport where there is free wifi). Trains make for easy public transportation to/from downtown. There is a large central park Parque Ibirapuera which we spent a morning walking around. The Mercado Municipal was highly recommended by locals. I went to the Museu de arte de São Paulo & would have loved to get to Museu Afro-Brasil. Check out Batman alley for graffiti. Favorite foods/drinks included: Cachaça de jambú (this particular kind makes your tongue numb), Pão de queijo, Açaí, Feijoada. Go out dancing (I hope your moves are better than mine!)
—> Rio de Janeiro
We took a bus (Brasileiro http://www.expressobrasileiro.com & 1001 http://www.autoviacao1001.com.br were the companies we used) from Sao Paulo to Rio, that was a good day trip (about 8 hrs: 9-5) and they do make a 30 min or so lunch stop en route. It was hard to purchase tickets online because we didn’t have a local code associated with our credit cards so we just took the train to the bus station one day in advance to book our trip.
We stayed at an Airbnb in the Copacabana area of Rio which we liked (Che Lagarto, the one highly recommended hostel, was booked out so Airbnb was option B) the Ipanema area would have been a good place to stay too, we liked walking to that beach. The place to go out is Lapa. One touristy thing we did was visit Selarón’s staircase in Lapa during the day & I found that I really liked that (if you like artsy things and can handle the tourists, check it out!).
Other spots which travelers/Brazilians recommended included Isla Grande, Paraty (we booked at the Che Lagarto hostel here but missed our bus & had to skip over to Rio), Minas Gerais and Trinidad.