One truck in many pictures has "Verpfl. Wagen" marked on the driver's door, which is "Provisions Vehicle".
Another truck is seen in a couple pictures with a sign hung over the radiator, "Abschleppdienst", which is "towing service" or "towing duty".
I deduce their initial training was in Bavaria or Austria, from there they headed east, with time for some tourist sight-seeing in Budapest. The river with destroyed bridges is most likely the Bug, then they passed through Kiev. The first fairly destroyed city is probably Kharkov, because it has a very big, broad flat central square in the middle of the city surrounded by taller apartment blocks.
When the shot of camels shows up, as a curiosity, they've clearly reached the gateway to the Caucasus.
I would guess the industrial facility with five smokestacks is possibly a power station, based on the transformer stations and transmission towers around it, but that's just a guess.
And then they cross the Don. The next stop is certainly
Stalingrad. He was lucky to get the photo album out in time, but the soldiers in the pictures probably didn't make it.