I'm probably not the best one to talk. Although I worked my way through college as a cook and owned a restaurant, I can only tell you about the basic foods I enjoy.
Breakfast - You will see a lot of what we grew up calling lunch meat. Different sliced meat loaves. You will see it served with breakfast along with sliced cheeses, granola, yogurt, and bread rolls.
Lunch - we always get a brat at a stand or eat a picnic of sandwiches made with more lunch meat, cheese and breadrolls from a grocery store. 100 grams each of meat and cheese is plenty to make a lunch for two. We add olives, chocolate, wine, beer, soda or water and find a park. The mustard that comes in tubes like toothpaste is really good for picnics.
Dinner - There are lots of choices in Pork. Bratwurst or Wienerschnitzel are also common. Sauerkraut exists but isn't really a staple. A potato salad with heavy vinegar flavor is common. Lamb, fish, game, duck or chicken are less common but you may see them on the menu.
Beer - Each area has the local brew. I suggest trying whatever they make locally, fresh beer is always the best and cheapest. Your choices will be Helles (light beer)or Dunkels (dark beer). There are local specialties such as Weissbier (wheat beer, hefeweissen), Pils (pilsner) and Kolsch (Cologne's style) as well.
Wine - The Rhine and Mosel are good wine producing regions, mostly white wines. I like the dry (troken or halbtroken) white wines. Most of the whites in the US are sweet. Again ask for the local wine choices. In the fall you can get new wine, it tastes like freshed squeezed grape juice so be careful not to overdo it.
Chocolate - Sold cheaply in grocery stores, the chocolate in Germany is great. I like one called Milch (milk chocolate in a purple wrapper) but you should try lots of different kinds and pick your favorite.