Young professional looking for room

Hi! My name is Rickard, a 24-year-old recent graduate who will be moving to D. C. in August to do a paid internship at a think-tank. For this reason I am looking for housing near D. C. from late August until the end of January the following year (so five months in total). I am originally from Finland, and would describe myself as a social and easy-going guy who enjoys doing sports, exporing my surroundings or just hanging out. I have lived in shared housing before during a stint in Belgium, and am looking for a similar arrangement with a private room in D. C. as well. My budget lies at max $1400 (though under $1300 preferred), and I am looking for somewhere either relatively close to downtown or somewhere that is well-connected by Metro. This could be everything from Dupont Circle, Adams Morgan or Columbia Heights to Navy Yard, Capitol Hill, H street corridor, Arlington and everything in between. I am primarily looking for places that are pre-furnished. Feel free to hit me up if you have any leads!