Welcome.
I do not know how elaborate you want to get but there are a few sites with N scale buildings and other sites with other scales that can be rescaled to N. That is what is great about paper models. You can generally rescale them to fit your needs.
Here is a German site with some nice buildings. They come in N and HO scale.
https://www.wediul-kartonmodelle.de/modellkatalog.htm
Here is a site with some buildings at OO scale you can print at 48% to get N scale.
Wordsworth Model Railway
There are plenty of models to buy that are in 25 mm scale which is around 1:72 scale in ratios. You can print them at 45% to get N scale.
It is best to print one test building and make sure the it fits, though. Some of the scale information differs depending on where you get it from, i.e. USA, UK, Europe mainland, etc.
