Ah, the problem you’re having is that you’re inputting your texture with Orco - it just projects your texture top-down onto your model.
What you need to do is make a UV map. Now that can be a fairly complicated process, so you might want to look up some tutorials on it some time, but for a mere plane such as this, it’s super easy.
Select your face in Edit Mode and press U. The UV mapping list will come up and you need to select Unwrap. This gives each vertex a coordinate on a 2D plane (which you can see in the UV editor).
Now that you’ve got that, you just need to tell Blender to use it. Go to Shading (F5) -> Material Buttons and find the Map Input panel - it’s in the same panel as Texture. Flip on UV, and Blender will turn off Orco. This should fix your problem.
If your image is still rotated in some way, which I don’t assume it is since it wasn’t when I downloaded your file, just go to the UV editor window and rotate the UV vertices around until they display properly.