If you live on the outskirts and need to take the bus/train or subway, you will get them full from 6 am to 9 am and the lines from downtown to the outskirts are full from 5 pm to 8 pm, peak time.
The bus lines in the center are good, you have AC, usb to charge your phone, and the
the time between one bus and another is ok, like 10 or 15 minutes, but in the periphery this time usually changes to 40 minutes, 1 hour or more, and there are old buses, without AC, but that is changing.
Train lines usually have a wait time of 5 or 15 minutes normally, but common problems occur on these lines (such as cable theft, power problem), and this time can be as long as 30 minutes or more. Another problem is the number of subways/trains that are very small considering the size of the city or state.
If you have the "Bilhete Único", you have free integration between buses (from one bus line to another), and pay a small fee (25%) from bus to metro/train in 3 hours.
The full cost of the ticket is R$ 4,40 or US$ 0.21. But this is determined by each city, this prices are from São Paulo.