Here are some Websites to find an own flat:
in each region exists local newspapers which normally are free of charge and contain information of local themes. In these newspapers exists anouncements of local workplace and apartments/houses.
in www.xing.de are local groups offering apartments, too.
you can join the FB group "places4refugees", where we published some advise for looking for apartments:
I also found this:
"we help you to move from the central refugee camp to your first ownflat on the platform
The platform works in arabic/english/french/german and gives Knowhow and email-support
Greetings from Pastor Andreas Dohrn Tel: 0170/7144931 Email: firstname.lastname@example.org"
Wg-gesucht.de helps with shared flats and it's used widely by students.
Who can also look to tje website