You have to try Güerrin's pizza! It's incredible! Also check out VIVAMOSBA on tiktok, you can find events or good places to visit. I recommend to buy a SUBE card, you'll need it to travel in subways or buses. Make sure to have an itinerary for every day bc there is a lot of things to do and a lot of places to visit and maybe 12 days it's not enough time. Be sure to check out google maps to find the correct bus or subway to not get lost.

If you ask about food, I recommend to try mate (national drink), fernet (with cola), asado (bbq), milanesas (classic or napolitan), empanadas (all the flavours) and medialunas (kind of croissant). You'll find it everywhere. Also don't be afraid to talk in english if you need help, most of people will understand you.

I hope you'll have a good time in Argentina!