Intership student looking for WG

My name is Guido, I'm 23 years old and I'm looking for a temporary room in Berlin, since I am doing an an internship at a Berlin Startup. I came to Berlin because I think the atmosphere is really nice and it has various nice places that can be explored. I study Artificial Intelligence in Nijmegen, which is a nice city in the Netherlands. In Berlin, I will do cool things with big data.

I love to meet new people. I am looking for a room in Berlin with some nice people with who I can have a chat and with who I can also spend some time (like eating together, or maybe having a drink together). I am looking for a room with either German or International people and I am capable of speaking both English and German. I play waterpolo, which I would also like to do in Berlin.

Any tips for finding a room are welcome, because I really need one for my internship (and staying in a hostel is not an option of course). (I have some savings and I earn some money from my internship, so I am able to pay the rent)