This is for Gearmánach - Kirsten. Perhaps you would like to have a look at this website.
http://www.braesicke.de/gaeilge.htm - Über die Irische Sprache
You don't say where you are in Germany, but if you have a look at the Irish Embassy in Berlin website, they have a monthly diary of Irish events and cultural activities that take place across Germany. For instance there are pubs in Berlin that host Irish-speaking groups and there's at least one blog in Irish by an Irish Berliner. Conradh na Gaeilge Bheirlín are on Facebook.
I don't know what book you have, but searching on-line I've found these -
Kauderwelsch Irisch-Gälisch Wort für Wort 978 38941 6797 4 (2013)
and the CD - 978 3 8317 6003 9
Irisch für Anfänger 978 3 8754 8574 5
Wörterbuch Irisch-Deutsch 978 8754 8124 2
The Learning Irish coursebook by Mícheál O'Siadhail has been published in German - Lerhbuch der Irischen Sprache and is still available second-hand 978 3 8754 8029 0, but strangely the latest edition with two CDs (2012) - 978 3 8754 8654 4 - isn't available.