It's impossible to say if "the video tutorial" is showing the correct procedure. Is it publically accessible?
Generally, I use the margins to determine where the page-by-page content area is--which is not the same thing as the live area. This does not include any header & footer area.
The live area is simply how close to the trim edge (the page edge) that the printer will guarantee not to cut off. This measurement tends to be overly large as many printers can safely trim within 1/8 or even 1/16 inch from the edge accurately. I didn't bother with them on my parent page since the other margins gave me all the information I needed. However, if I did need the live area margins, I would use ruler guides.
By default, margins are pinkish color and ruler guides are blue/cyan. It looks like you just have margins set. Consider learning how to do a screen capture rather and taking a photo of the screen.
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