Looking for a Room to Rent

Hello! I will be arriving in Spain to begin work as an English Language Assistant on September 2nd, and I am looking for accommodation in a shared flat. I am 21, female, and easy to live with! I want to socialize while in Spain but I am a very low-key person (not looking for lots of wild partying). My school is on Line 5, so ideally I would like to rent a room in a flat that can easily reach Line 5, and my budget is, at the most, 500€ a month.