Get a Tom Dowie course, cheap and he’s one hell of a good coach.
To answer your main question, Yes and No. Yes you can learn some stuff of reading or watching it online, but basic stuff since you don’t have a professional showing you how to do it and spot what your doing wrong.
That said, I did learn to jump and to corner quicker from watching youtube videos but when I got professional coaching he took my technique and threw it out of the window and completely reshaped my Jumping and cornering. Also Alot of videos/articles don’t tell you what could be going wrong and how to sort that out. Not a single jumping video shows you how to pump they all tell you to pull up and keep the bike level. This is wrong. Get a coaching course, Tom dowie coaching is priced nicely and you will learn more in 2-4 hours then months of doing it on your own.