If you need to relax a bit, São Paulos equivalent to the Central Park, the Parque do Ibirapuera might be the place for you. It is a 160 hectare park with ponds, woods and lawns where you can relax, do some sports or look out for art.
The park was created in the 1950s and was built by Oscar Niemeyer (pavillions) and Burle Marx (landscape). The people of São Paulo use the space for sunbathing, picknicking and reading. But under the Marquise do Ibirapuera, a futuristic roof, you can still do skating while it is raining.
Or you can visit the Museu de Arte Moderna de São Paulo, located next to the Marquise. The Fundação Bienal de São Paulo even has its headquarters here. A quite surprising sight is the Japanese Garden of São Paulo, next to the pond. The Japanese community created a classic Japanese house, a stone garden and a pond with koi carps.
To get to Parque do Ibirapuera you can walk from Avenida Paulista, but it is a long hike. If you dislike to take a taxi: Metro station Brigadeiro is next.