I would like to seek your advice on how to travel from Gengenbach to Luxembourg. I ordered a ticket on DB Bahn website for a trip from Gengenbach to Luxembourg in May. The ticket I received by post shows a partial trip from Hanweiler to Luxembourg which cost EUR 12.40 and a seat reservation on Bus 123 from Saarbrucken to Luxembourg. I don't see Hanweiler in the itinerary of my order which should be Gengenbach - Offenburg - Strasbourg - Saarbrucken - Luxembourg. It seems that this route is shortest and scenic, that is why I chose it. The route says border crossing at Kehl(Gr), Hanweiler(Gr), but I can't find Hanweiler along the border.
Can I use the ticket (Hanweiler - Luxembourg) already bought and buy tickets for other sections in advance? Or should I just arrive one stop then buy tickets for the next stops? Any tips on saving costs are much appreciated. I have contacted DB Bahn via email, asking them to explain my ticket situation but no response so far. Thank you very much in advance.