German. Most people understand English. Many people from Denmark visit the Flensburg region for shopping, therefore it is possible also to speak Danish there.
Use public transport like the different train companys or bus services. Public transport(only german)
Visit Ditmarschen and eat the fabulous seafood. Try Friedrichskoog for great fish restaurants.
Shrimp: in Büsum, you can buy small boiled shrimp by the kilo. Spend a happy communal time peeling them and eat them on black bread, with a fried egg over the top. An excellent abend brot (dinner) or snack!