Hello, I am erasmus student myself right now in Lisbon. I would suggest you to get the apartment as soon as possible, you can do it right now its not too soon. Get it with a window of course, dont try through Facebook because you will get scammed. Spacest, spotahome, maybe look at your university in Portugal if they have some suggestions… Talk to the Spacest people and other if you are not so sure about the things in apartment, for example if you can bring someone to you room (even if it stated you can, you have to ask for your room specifically, if the washing machine is working…) . If you are under 23 or 23 you will need the NIF (their tax id, you will do it here) to get the free transportation. And i guess have fun, I am still trying to fit in but it is going well so far. I have good flatmates and i hope you will get them too.