When you're ready to get the bill in a German restaurant, lay your utensils across your plate to let the wait staff know you're through, then specifically ask for the bill. They probably won't give it to you until you ask, as that would be considered rude.
One thing you'll definitely need to produce authentic German food is a metal meat hammer. Schnitzels are an important part of German cuisine, and they consist of thickly breaded meat cutlets that are pounded thin to help make them more tender.