What is the legal ruling regarding taking 10 Euros found in a commercial shop in Germany, and is that considered theft, and what is the ruling on taking magazines designated for reading from doctors' clinics or lawyers' offices?

The money must be returned to the shop owner, because the basic principle is that whatever is found in a person's possession belongs to them. This money is considered an encroachment on someone else's property, not theft. Your duty is to repent to Allah and return the money to its owner. It is not permissible to take magazines that are designated for reading only, such as those found at doctors' offices and the like.