That will be hard for you... The Germany law are almost like every European Country law. In few words : You can't use drone.
You will need a lot of authorization and flying licence. It took me like 3 months to have all documents.
But, the controls are low, very low. So if you attempt to fly anyway, please follow this simple advice :
Don't use drone in any towns.
Visual flying only (keep an eye on your UAV), don't use for immersion flights.
Don't move away more than 100m
Don't climb more that 150m
Don't fly over people/animals
Respect a distance of 30m from people/animals.
Fly only on wide space like country side, forests, fields... No city, no castle at all.
Write your name/cell phone on your UAV
If police comes, don't run... Try to "explain" them why you want to practice drone.
If you want to fly over big town like Frankfurt... You'll need a special authorization and You'll not be able to get it as you are not German and you are not professional.