VBefore the trip you have to do some research. The Robert Koch Institute and the Foreign Office do not prohibit travel, but they do not make it easy for you either. Detailed lists of the states and regions for which a travel warning applies are published.
Conversely, you have to find out for yourself which countries still allow visitors to enter the country and whether there is a quarantine obligation when returning to Germany. We have made the effort for you and here is an overview.
Iceland is currently the only complete country in Europe for which the Federal Foreign Office has not issued a travel warning.