Could you please recommend me a modeling course that would be well suited for eventually learning to make models like these? 
I know that there are many basics I need to learn, it would take months or years, I did make some crappy anime heads a few years ago in Blender so I can see how much effort it's going to be. Just wondering if there's something good, though of course I know it's not going to be specifically VRChat anime models from booth.