Thank you very much for this help. :-)
I came to the conclusion, that it is better to use the english version of the program instead of the german one. Otherwise you will not know the matching word for searching in the help and online, i.e. using "arrow" instead of "edge".
But some things remain german, i.e. in the "View" and "Layout" pulldown menü the words "Tastenblock" and "Umschalt".