Need single room for long-term stay in a shared flat from Sept, 2018 below 500 euros in Bonn

This is Tasha from India. I will join as a Ph.D. student at the Max Plank Institute for Radioastronomy in the University of Bonn located at Auf dem Hugel in Endenich, Bonn. I need the room for a long-term stay of about 3 to 3.5 years, preferably a 2-3 room shared apartment under 500 Eur. I am usually a quiet person who understands the importance of personal space and would expect my flatmates for the same. You will mostly find me reading and enjoying nature. I also enjoy the company of friends and would love to interact and learn from people of different cultures. It will be my first travel to a foreign land so I would love to travel and explore as much as I can and would love to have my roommates along with me!
I like a clean place but I am not obsessive over small stuff lying at wrong place too. I am trying to learn German(started about 2 weeks back :-P) it would be nice if I could practice it with my roommate too!