When you drag a OBJ MTL and Maps folder to Assets, how do you get them To be Textured automatically?

I always drag stuff and they don't always get textured automatically. The textures are there but it just doesn't happen.

And this is especially difficult when you yourself would not eve know what texture goes in what part.

For example a city, it comes with tons of map textures i dont really know where to drag them to to make the city model be textured.

Here's an example of a city i found and downloaded.

Not just thisi model. there's many other OBJ or 3DS models which i drag to the Assets and when i drag to viewport, they are not textured.

These includes cars , houses and more. And i do also drag their Texture folder