A 21year old Lithuanian guy is looking for accommodation in Barcelona from end of June to October

Hey, my name is Gabrielius. I am from Lithuania and I am looking for a place to live for 3 months in Barcelona. I am 21 years old. I will be a trainee in one Barcelona's company. My arriving date is 27th of June and I will stay in Barcelona for 3months - to the 30th of September. I am a calm, non-smoking guy. I'm looking for both native and foreign roomates or flatmates. The first ones could be my mentors in a new city, the second ones could my partners in a game which is called "To Get Lost In A New City". In other words - I like to explore new cities and countries, yet I need my small private place sometimes.