German Rail does not sell Chinese food (Happy Family).
Prague is in the Czech Repubic; Strasbourg is in France; Munich is in the state (Land) of Bavaria in Germany. Rothenburg ob der Tauber is in Bavaria. Not sure where Rothenberg is, but if you are using Rothenberg, and not "Rothenburg ob der Tauber", you will have trouble finding connections on the Bahn website. In fact, if you want to go to the train station in Rothenburg, you should put in "Rothenburg ob der Tauber Bahnhof", to avoid getting a list of bus stops in Rothenburg.
Best way from Prague to Munich:
There are three 6 hour connections daily from Prague to Munich. Some are direct (no change of trains); one or two change trains in Schwandorf. These are regional trains. If you can purchase a Bayern-Ticket in advance, either from the Bahn's online store, or earlier from a DB automat or counter in Germany, you can buy tickets in Prague for Prague to the Germany border (at Furth im Wald) for about €10-12 pP and use the Bayern-Ticket from there.
There are many ways to get from Rothenburg to Strasbourg, but most go through Stuttgart, which is in Baden-Württemberg. If you stay on regional trains, you can use a Bayern-Ticket and a Baden-Württemburg ticket to get to the German town of Kiel, across the border (Rhine River) from Strasbourg and P-P tickets from there.