Solo traveling for the first time! Going to São Paulo, need safety tips & advice!

First of all I hope whoever reads this & shares their wisdom/tips has a very joyful & prosperous day, good morning! So last year I met a girl in my city from São Paulo & we instantly hit it off. We spent time with each other for 3 weeks! I feel as if she’s the woman I want to spend my life with & she makes me really happy. I currently am unemployed so I decided to book a trip now that I have time off from the refineries after a 9 month long turnaround. We met in August 2021, then in November 2021 we met up in Cancún (I helped with her flight) & we had fun for another week. I will be traveling to São Paulo on September 23rd- October 4th to see her & it’s my first time ever solo traveling, let alone to another country. I’m not fluent in Portuguese by any means, but I do understand it. I’d like to know the pros/cons of SP, what to do if I do get my phone robbed or credentials (I think its important to realize it could be a possibility of it happening) & maybe put my worries to ease. I booked a airbnb in a condo close to the airport in Guarulhos (because of her proximity) & I’d just like to know a little bit of the city & places that are safe for a foreigner. Also if you guys have any suggestions of places to go to I’d love that as well. I simply do not want to ruin my fun or trip, by being paranoid & being too worried. Thank you guys 🥹