It was a matter of putting all the clues together based on everyone's input.
First of all, 4.13.1, Windows 10. QLC+ app is in the default location, which is in the QLC+ folder at the root lever of the hard drive. And my show files are on the desktop.
Someone mentioned if the show file name has any spaces, it has to be enclosed in quotation marks. Didn't work. Then I tried moving the desired show file to the same folder as the app. Then it worked.
But then could not get it to work with the desired show file on the desktop. Someone mentioned you have to include the file path. Still didn't work.
Finally I tried enclosing the show file name AND the file path in quotation marks and it finally worked.
So in the end, it looks like this: -o "C:\user\user\desktop\Desired File" and add -k -f -p as desired.
But for what I'm using the kiosk mode for, there is just one show file, so I'll just put it in the same folder as the app.