I would stay you've got a good start here. I would recommend the book How to Draw Comics the Marvel Way. It can be found cheaply online if you don't mind used. Its a bit dated, but the foundational stuff doesn't change. Perspective, Anatomy, Composition, Manaquinization and Basic lightting are all in there. Exhaust this book and it can get you far down the road as a beginner. As you gain skill you can look to study more thoroughly these subjects in other books and courses. Don't be afraid to copy but do it the right way. Copy to study ,so pic something that you like by your favorite artist and copy it. It could be the way they use line to create volume or the way they design something like a masks or poses. Then do your own drawing from what you've studied. Apply it! Finally I would say David Finch has great videos on Youtube for comic artists. And Proko has courses by him too. Try to exhaust the free stuff on Youtube first, though. He really is a great example of Zero to Hero and I greatly admire his work and ethics.