but "Zug" is mostly used for "train, move, platoon, breath"
the rest are special cases, which you don't have to know, you can find them out of the context.
It's probably the cases(nominativ, Akkusativ, Genetiv, Dativ) that bugs you, and I think the 16 possibilitys of "the" an the 9 of "a" are issued from the different cases.
I can imagine that's not easy, if you never used something like it