Sao Paulo has different centres.
The old downtown is where Catedral da Sé is, and the adjacent area, where you will find many lovely sights of old sao paulo.
I know there is a walking tour, but I can't find the website now! There is this one with some good tips on sightseeing:
…terra.com.br/turismo/ingles/dicas.htm. and I found a telephone number for the walking tour: 0/xx/11/ 3241-5822 (ramal 221).
The main attractions there (that you should really look for): Predio Sede do Banespa, (the mini empire state building!) has a wonderful 360 view from the top. If you want a meal with a view, go to Terraco Italia. Good Italian food and a wonderful view, they have an afternoon tea for R$25, which will allow you to not spend much, have a nice tea and appreciate the view. Mosteiro de Sao Bento, for great barroque religious art, and also for a fantastic santa escolastica cake or a bolo dos monges.
The Theatro Municipal is also beautiful architecure, worth seeing. I also love the Mercado Municipal or Mercadão, with all the lovely fruits and vegetables and now apparently they have some nice restaurants there too!
Old downtown is probably around 20 minutes by taxi from where your hotel is, but in sao paulo heavy traffic jams makes it impossible to say how long it might take you to get there!
I dont know exactly where your hotel is, but from the name it must be close to Avenida Faria Lima, which is close to 2 main shopping centres (elegant ones I might add) called Iguatemi (has Tiffany's and Armani's if you like) and Eldorado (on Avenida Reboucas)
It is hard to place this as not downtown, because it is a main hub of avenues that makes the centre of sao paulo. It is pretty close to Av Paulista, where you can go to MASP and the Trianon Park. For a great young funky place try Spot for a meal.
For a typical brazilian, the feijoada, go to Figueira Rubayat, Rua Haddock Lobo, 1738. For more typical food, try dona Lucinha, Av. Chibarás, 399 - Moema.
Must visit Liberdade, the Japanese neighborhood, on sundays there is a street fair, with nice japanese food at affordable prices!
I could go on and on. I just love it there.
If you need more specifics let me know and I'll try to help.