The video didn't help because, His was a sprite sheet and it was easy for him to drag it in. The file I bought here doesn't show up as a sprite sheet for some reason. if that makes sense.
Can you take a screenshot of the file?
And so I have a couple of guesses. Either you downloaded the ase archive instead of MinifolksOrcs, or you just don't have an archiver and you can't unpack the archive.
I downloaded both and I think I don't have a archiver. I have never had to use one before.
Personally, I use 7-zip, but if you don't want to download anything, you can send me your email address and I'll send you the unpacked files.