I’ve been modeling for a long time and working on a game with a lot of modeling and buildings to make so I tried my best at making a simplistic one. If you are a fan of HxH you might remember this, give feedback on improvements etc.
Also where can i find lowpoly textures like (Third Picture)
It’s really good! Being a first building, you have made it pretty good!
Looks Great! as for your question I am not sure where you can find textures, but you can always make your own textures in paint 3d or something like that.
Amazing!.
You are very good building.
Really, but really good start! There are not too many details, so It kept that cartoony look, I mean It is perfectly balanced.
The only thing I would recommend (If you’re not using a texture) to add roof tiles! It will look incredibly good on this building 
Goodluck, buddy!
add more shapes, use subdivide if you want more realistic look and keep practicing try and make a sword or something.
I love the style, keep it up!
Here search your texture
maybe edit mode > vertices > and add more vertices
