Unable to answer "What kind of building is this?" for https://osm.org/way/762707025 via StreetComplete 21.2:

This is the old train station from when there was passenger rail traffic. That ended in the 60s, so I think it's just used for storage and an office/way station for railroad workers.

Attached photo(s):
https://westnordost.de/p/16081.jpg