I'm then going to mask it so the sky is hidden and therefore there's an empty portion of the image. Well, I can't combine multiple images using just like Trump, so I need to open this image into Photoshop.
Why wouldn't you want to do that? Well, in this case for this picture, I find the simple blue sky to be rather boring, and I'd like to substitute a different sky.
Now let's take a look at how we can overlay images that were made in Photoshop onto other images that we have in our light room catalog.