Q: After I saved my pictures onto my PC, there is a .AAE blank file after every picture

The AAE are "sidecar" files that contain the edits. The original pictures are retained in the JPGs. If you want to preserve the edits you would have to import your pictures, not copy them but some versions of Windows will not import the edits at all.

Import photos and videos from your iPhone, iPad, or iPod touch - Apple Support

There should only be an AAE file if some sort of edit has been made, by you or the phone, like HDR or scenes. I hardly get any because I seldom edit with the phone. I leave my editing to the computer.

I don't know.