It was a whirlwind to take Drawing II at the community college with four hour long classes held four days in a row. Plus homework. I gained a few more pounds due to missing good lunches and eating in restaurants for dinner as I was too busy to cook from scratch. And eating candy bars for fast energy when fading fast in class.
I learned things in the class during the lecture and other things from directly talking to my professor during class with 1:1 help. I also had more reinforcement about what I already knew or suspected about how to learn and how to master something. I already knew things from my own life experience and also from self-teaching and from having homeschooled my children. So much I am now hearing and seeing I already knew, such as the following:
It is okay to make a mistake. Learn from the mistake.
Redo (redraw) the same thing to try to get it right, redraw over and over until you nail it.
Drawing teaches the foundation needed for painting, animation and digital art. You must know composition, value, proportion, perspective, and figure drawing to do all those things unless you plan to only be an abstract painter. If you want that you still need to know color theory or have some natural talent for it that didn't need instruction.
Practice, practice, practice.
The way to mastery is intentional practice. So if taking a class don't just do the homework and move on when the deadline is over. Keep practicing on your own.
Classes do not give enough practice before moving on to the next thing. Extra work outside of class or done after the class ends is what helps you improve.
Mastery comes from your own motivation and drive to get things done. If you only work when you have a deadline from someone else it's not enough. You will not get good let alone excellent.
Many of the successful working artists (including animators and video game character developers) have their foundation in the traditional art education as taught to fine art students. A human like monster needs a body and you build out from there. You don't start with the costume then do the body parts. So, traditional figure drawing is what is required to draw humans and monsters from your imagination.
Daily practice is essential even if it's only sketching your surroundings or figure drawing in gestures.
Information can be in books and you can self-teach but you probably won't see your flaws and/or know how to fix them. Therefore a (good) live human teacher is essential.
Books for self-teaching only do so much, it really all relies on practice. Owning the book will not make you good, and reading it once won't work either. Practice, practice, practice.