As a YouTube novice, trimming away unwanted portions of my videos proved to be a challenge.
It seemed I was on the right track by using the “Edit” button, but for some reason the edits wouldn’t save.
Then it finally occurred to me to seek out a YouTube “help” video that would hopefully explain, in simple terms, what I was doing wrong.
That video is here: https://www.youtube.com/watch?v=rXnI0N5djxA&t=51s
It turned out that there was one small thing I hadn’t done correctly to complete the process.
I have now begun the process of editing all of my early videos for a more professional look.
That is not to say that I still do not have much to learn!