A 23 year old guy looking for an apartment in Barcelona

Hi,

As the title states, I'm 23 years old (a guy) from Finland and I'm starting my studies this August at the 25th day. I'm arriving in Barcelona approx. at the 21th day of August. I don't want to stay in expensive hotels so the best thing for me would be that I could move in the day I arrive. I'm still unsure when I'm going to leave in January but most likely somewhere after the 18th day.

My problem is that I haven't found a reasonably priced apartments. My budget is around 300e/month all costs included and the most I can stretch the budget is to around 500e/m.

My "special" needs are that the place is furnished and that there would be Internet connection. I can be flexible with other requirements or deficiencies the apartment may lack of. 

I'm a chill dude and I can get along with almost anyone :). I'm pretty fluent in English (and of course in Finnish if any Finns are around). I also speak very little Spanish and I don't mind learning the language more.