Textures Not in Textures Folder

[Lenilur]

I can't find any textures in the textures folder. I am new to making mods (this is my first try) and I was just trying to make a gun, but I can't find any textures.

 

Or, an easier way would be if I could just copy weapons and just change the stats, but I don't know how to make a copy of a weapon.