I didn't watch the video (hate videos, the info flows too fast) but believe in learning by trying.
I'm a PS beginner but have used it for 30 years or more. It is the most miserable app I know. But it can do things, so I use it.
I keep a "recipe book" with detailed instructions, written mostly by myself, for specific PS tasks. For instance, there is one on focus stacking. There is another one on color separations. Just recently I added one on placing a person into a scene.
PS says with a smile that it's easy. They lie. It's notable that they need to point out how easy it is when they know it is very hard. LOL. How many people on your block can work PS with facility? Probably none.
I also use the beta version of PS, like SquarePeg. And also like SquarePeg, I find it works great at times but fails at other times.
Photoshop, like practically all programs, uses a hierarchical menu system. If you are looking for some command, you may have to hunt through them all to find it. Or go to Google. How do I remove/delete a selection? Where is the "remove" tool? Oh, it's called Clear, and it is under Edit.
A year from now I'll have to do the same and will have forgotten. But no matter! It is in my PS recipe book now!
But it's so easy! Need to remove a background? Just click on Remove Background under Quick Actions. Problem is, sometimes that entry isn't there. Spend 20 minutes looking for it and finally go back to Google.
Maybe one day PS will be task-oriented. Then we will type "Remove those ugly wires in the upper right" and it will proceed to do that, hiccup-free, with the user providing the necessary guidance for the desired result.
In the meantime, I will rely on my hard-won recipes.