Guarda is close to Porto at 3 hours away by bus also 5 hours to Lisbon by bus. You can go to Spain(Salamanca or Madrid) from Guarda easly. If you will come to Guarda to study and would like to trip that I suggest all of you that you should buy the ticket from Madrid because the ticket price is usually 10 euro to go.
If we talk about the accommodation, you have to take mail to Isabel Calçada who is interested the dormitory and home if you want to stay these places. These are cheaper than another else because you only will pay the rent ,1 bed just for 80 euros per month
Finally the classes, Guarda isnt the best place to study, the classes in my opinion are easier than other places, but you can still learn a lot about all the subjects.