23 years old male erazmus student, looking for accommodation in Porto (Portugal)

Hey everyone!

I'm an art student, and I'm going to spend winter semester studying at Universidade Católica Portuguesa in Porto. I'm mainly looking for a studio, but I would also be interested in finding a shared flat with my own room, located in the historical center, or at least at the city center. 

As a roommate, I'm quite tolerant, I don't mind smoking, having pets or coming back home late at night. Besides the good location, I expect only elementary facilities in the flat, like: water, gas and freezer (internet connection would be nice too), the size of an apartment and other facilities don't really matter.