Moving to sao Paulo

Hi!

About the neighborhoods,  I would advise Itaim Bibi itself, Jardim Paulista, Moema, Pinheiros, Vila Nova Conceição... Pretty much every neighborhood you see around the big park "Ibirapuera" (check on GMaps) is great. (See screenshof if the regions I would advise here https://ibb.co/0rTZT5W)

Mostly, I would avoid the city center (Republica/Consolação).

One thing to note, traffic in Sao Paulo during peak hours is REALLY bad (7-9am and 5-8/9pm). If you plan to go to your office everyday or so, having a metro stop nearby or living really close to your office should be a top priority.

About the cost of living, it gonna varies a lot depending on your lifestyle and how lucky you're gonna be with your flat search. I live with my girlfriend in a decent neighborhood (though no dog!), we're going to the gym and go to restaurants/bar probably 2/3 times a week, so I think it's fairly close to what you're looking for!

The neighborhoods I listed above are very nice, but they're also the most expensive. Unfortunately for you, Itaim Bibi is probably the most expensive of them all

For a flat of 2 persons, and say furnished, with a minimum of 45/50m2, 1 bedroom, you'd be looking at a minimum of 5.000R$ per month. But that's becoming very rare. In Itaim you'd probably be looking at 7.000R$ per month minimum. In Pinheiros/Jardim, you can start finding decent stuff around 6.000R$ per month.

So I would plan on a budget of 6000/6500R (~1100/1200e) to be somewhat confortable. If you want to look for yourself, the most popular site for flat searching in Brazil is Quinto Andar

Then, about the rest:

• Gym : A basic membership to a popular gym is gonna be around 100R per month (Smart Fit is the most popular here I guess). It can become super expensive if you're looking at places where you can play sports (football/basketball/swimming etc) though.
• Bills: About 150/200R per month for internet and phone plans. About 200/250R per month for Gas and Electricity.
• Going out:  We spend usually have a bill of about 350/400R total for 2 persons (with a full meal and some drinks) but it heavily depends on the place you go obviously. A Cocktail in a nice/cosy bar is gonna cost you about 50/70R. A bottle (600ml) of beer in a regular bar is gonna cost you 15/20R. A plate in a nice restaurant is gonna cost you 70/90R.
• Daily food: One week of groceries for 2 persons is usually about 300R for us, so say 1200R a month. We also order from Ifood (local Uber Eats) a few time a month. Ordering on there is going to cost about 100/150R for 2 persons.
• Also plan to spend a decent amount on Uber as a mode of transportation, it's very common here and way cheaper than in the EU/US. We spend about ~350R per month on it, but we're also using it for absolutely everything.

So, without too much extra activities like travelling, I would say that for a good day to day lifestyle in Sao Paulo, including everything (nice neighbourhood, going out "often" etc) I would plan on a budget of 12.000/13.000R (~2200/2400e) for 2 persons minimum.

Sao Paulo has a LOT of restaurants  / bars and a very active night life, so if you have the budget for it, I would definitely spend more on this. It's one of the biggest city in the world, it's so vibrant and there's a lot to do so I would take advantage of it if I could ! But it's more expensive than anywhere else in Brazil

it's my personal opinion, but if you're not someone that likes to go out to try new bars, restaurants, clubs, festivals, brunchs, date night with your partner etc., or do not have the budget for it, am not sure Sao Paulo is the city for you ! But if it is, it's probably one of the best in the world in my opinion, and I tried a lot of them