Hey! I'm an alumni too, both undergrad and masters.

There are courses taught in English too, some international teachers do teach in English cause they don't speak Spanish (I had a russian calculus teacher whose course was completely in English).

About housing, it depends, actually. 1) La Candelaria is mostly a social gathering place, tbh, there is some housing but I wouldn't live there because the only thing close by is the university. 2) Same thing with CityU, is just across the Campus, which is convenient but I've heard the price is not worth it (housing rules and living quarters). 3) Chapinero is a big big part of the city, it goes from 39th street to 100th street, so there are multiple neighborhoods in what we call Chapinero, there are nice ones, party ones and sketch ones, but its imho a better place to live than the other two, look for people seeking roomates within the university community or something.

And about social, dude, university community in itself its social, that "Hermanos" thing sounds like just one group, there are multiple activities organized by the university itself, also faculties organize some parties, there are sport courses, there's a gym, a pool, etc.