Sir,
I would suggest you look into two resources:
The first, for martial arts, is the European Shivworks Camp (
https://www.eventbrite.de/e/european...ts-51018806624). Every year Craig Douglas aka Southnarc of Shivworks, whose videos you can see above under ECQC and Edged Weapons Overview, comes to Germany to put on what is probably the best reality based self defense course you can find, concerning not only unarmed and knife self defense but also how to avoid and deescalate confrontations from happening in the first place. I would strongly consider attending if possible.
The second resource is Oliver Falk at Viking Tactics Germany (
https://www.vikingtactics.de/). He is the German affiliate of the world class Viking Tactics training company run by former Delta Force soldier Kyle Lamb, and also an accomplished IPSC shooter. He will likely be able to tell you the best way to get involved with tactical firearms training both in Germany as well as abroad.
Hope this helps, welcome to the forum!