How do you add custom textures to objects? (Unreal Engine)

I'm fairly new to using Unreal and have been trying to figure out how to add custom textures to objects. I've been trying to create a street just to start off with and so I created a simple model in blender and then imported that into Unreal. So now that I have an object to work on I have been trying to add a simple texture to my street (just a black rocky texture with some yellow dashed lines down the middle). However I have been using the Unreal Engine's material creator which is quite frustrating to …