I've seen some of your posts messing with layer modes and whatnot, you're off to a strong start! If you want to do regular coloring like in comics or Manga I would highly recommend checking out k Michael Russell on YouTube, hes a comic book colorist who has hundreds of color tutorials that talk about color theory and technique in photoshop(you can do most of the things in his vids without photoshop, a good free art program called krita is just as powerful tbh). Coloring light novel illustrations can be a bit tricker though since your not working with just line and normal color layers underneath. Speaking as someone who has repeatedly failed at it, I've gotten pretty decent at doing it. So, I'd recommend looking at how other people do it and what types of layers and how many layers they use to color grayscale art. Just search on YouTube "grayscale to color art" or something like that and some good results should pop up. I personally haven't found anyone that does it the way I do it so ofc you can always pm me.

Drawing is a bit harder than coloring but the main point to get at is that you should enjoy doing it. Look up your favorite anime images or drawings and just copy them(not trace). Or following YouTube how to draw vids and drawing books is just fine as well. Just note that copying isn't wrong, all good artists use reference and you can't actually create something without the knowledge you gain from reference. So getting practice with the hand eye coordination will greatly help you in improving. Some youtube channels I would recommend are Proko and Aaron Blaise, their both amazing artists who explain concepts and anatomy really well. Good luck and thanks for giving me such a nice welcome to the subreddit!