Considering PhD in Barcelona

I am considering applying for a PhD position in Barcelona (at the ISGlobal). I spent a few days in Barcelona a few years ago but I weirdly remember nothing (it was a school trip). I never studied in a big city, so I am scared of not being able to fit there. Plus, based on some posts I read, it's difficult to live in Barcelona with a graduate student salary (but I don't know what the salary would be at this institute). I would like to know whether it's possible to commute from neighboring cities (smaller and perhaps safer?). Is it possible to rent a small studio apartment (I really don't like sharing apartments with strangers)? Thanks.

It's been a while since you posted, have you found more information? There are definitely small studio apartments, but they're not going to be cheap. (Well, they weren't -- prices are coming down a little bit though.) Since you mentioned the institution where you'll be studying, I checked their website and they have quite a bit of information there on transportation and housing: https://www.isglobal.org/en/estudiar-en-barcelona. Good luck with your possible move!