The Department of Business Studies is situated on the new HSD campus in Düsseldorf Derendorf.
You can find the address and maps of the new Campus Derendorf on this central page.
There is one student cafeteria (Mensa) which offers cheap meals at lunch time. There are also several cafés and other infrastructure dotted around campus.
Sports facilities are available on the campus of the Heinrich-Heine-University, and there is a wide variety of courses on offer www.uni-duesseldorf.de/hochschulsport.