So, here are the components of a German breakfast.
First, you need to get a bunch of bread. Sometimes I buy a loaf, which I consume over a couple of days, but what is more preferrable is one buys a couple of small pieces of bread on the day they will be eaten.
A couple of types of spreadables should be available, like jam, chocolate spread, peanut butter, butter, and honey. This will go well with the bread.
Then, there should be cheese, as well as some deli meats. Deli meat spoils after about a week, so do not buy more than what can be consumed in a week.
There should be tea or coffee, and some people also would want a glass of juice. Sometimes, I also prepare some eggs. An egg cooker would be very convenient.
As you can imagine, a German breakfast has plenty of moving parts. The table is set with all of these things, and the breakfast effectively becomes a buffet. Unlike the breakfasts of other cultures, the German breakfast is heavy, and pretty much a very important meal of the day. I actually like it, as it allows me to eat big in the morning, not so big for lunch, and light for dinner. Of course, when I am alone, I don't set the table with all of these parts (I don't make eggs, for example). And I usually just drink the juice, but not the tea.