That’s depends if your going for realistic textures or custom ones since I’m not kind of builder. You could find a texture pack in free models and play around with those and see what suits your liking. I’m not sure where to find textures your looking for, but the developer forum has some good resources for free texture sites that you can find any type of textures your currently looking for.
I would recommend checking out this thread you might find some interesting sites you could pick and choose Free texture sites: