I learned Photoshop by taking a $10 course on Udemy. It was on sale at the time but it was comprehensive and I learned everything I need to know. I suggest going there or Coursera and seeing if there are any courses for sale right now.
I added to my photoshop skills by basically following ANY tutorial i liked the look of, step-by-step. I did have photoshop knowledge already, but im sure there are various levels.
When i followed the steps, i kept a notebook by the side of my computer, and paused the video to write down notes and tips to help me memorize important functions etc.
I still do it from time to time to update and improve.
I dont have particular youtube video links for you, because i really just randomly choose.
But this is what has worked for me.