I learned a lot of stuff on YouTube. It was an annoying process since I had to figure out which people were saying the right stuff and which people were peddling garbage (there's a lot of angry people and a lot of pseudo intellectuals on the web).
For comics, I originally had a book that taught me how to write scripts until I signed up for a DC Milestone contest so I could get a job... but I never did. I did borrow their format though so I can be prepared just in case I do.
I think the only help was with this one dude who kept pushing me to fail and this Australian artist who reads my comics to this day.
Music also taught me. Breaking the lyrics and beats down. I think of stories as songs in a way.
I also like to break down the stuff I read/watch and figure out what works. I remember a book editor friend being shocked that I figured all of this and I didn't go to writing school... or paid attention in writing class.
There are downsides to how I do stuff though. For example; I don't know writing terminology. I remember one time when I was trying to give advice to a person on Discord with this other writer (that I can't remember), the other writer was dropping terms left and right. I tried doing the same, but I ended up sounding like a newbie lol.
It also took me... until I was like 19 or 20 where I use punctuations correctly? And even then I still suck at it a little. I had to study on sites.