São Paulo's traffic is among the worst in the world. Plan around it, and use the Metro wherever you can. The system has six lines that cover most of the central and middle-distance neighbourhoods you would want to visit — Paulista, Sé, Liberdade, República, Vila Madalena, Pinheiros, Faria Lima — and runs from 4:40 AM until midnight Monday to Saturday, and an hour later on Friday and Saturday nights. The CPTM suburban trains extend the network outwards.
For places the Metro doesn't reach, Uber and 99 are cheap, reliable, and far safer than hailing a street taxi. They are the standard way for visitors to move around at night. Buses cover everywhere but are slow and difficult to navigate without local knowledge.
Driving in São Paulo is not recommended for visitors. Parking is scarce, traffic is brutal, and the city's rotating license-plate restrictions make it confusing for first-timers.