21 student looking for a room/studio/shared flat in Paris

I'm a half Belgian, half Indonesian 21 year old student. I am coming to Paris for my last semester of studies after having spent the last months in Indonesia working for a start up. I am used to travelling a lot and am very happy to be living in new cities. I previously lived in Seoul, South Korea where I pursued my studies and shared a flat with other students there. Things worked out perfectly as I am very easy to live, so I would be very happy to do that again. Otherwise, I am looking for a simple apartment near any metro station, but preferably in the center of Paris. I don't really care about the size of the room (a small room is fine for me), I'd rather have a very small room in the center than a big one outside of Paris. Since I'm not making money yet, I'd prefer to pay a decent rent! Knowing that's a hard thing to find in Paris, I'm looking for an apartment/shared flat/room costing between 500 and 700€ per month. If you know anything, please contact me, I'd be very glad to hear from you! 

Thank you very much for your help,

Celine Van Schoote