São Paulo sits 70 km from the coast and a couple of hours from the Serra da Mantiqueira mountains, so there is plenty within day-trip range — though the traffic getting in and out of the city often eats the morning. Guarujá and Santos on the coast are the standard beach trip; the road over the Serra do Mar through Cubatão is one of the more dramatic short drives in southeast Brazil. Embu das Artes is the closest historic colonial town, a short drive west, with a Sunday craft fair.
For mountain air, Campos do Jordão in the Serra da Mantiqueira is two and a half hours by car and the closest thing Brazil has to an alpine resort — colder, with European-style architecture. For a more cultural day, Paranapiacaba is a preserved 19th-century British railway colony perched on the escarpment, two hours out by train and worth the trip.