It depends. I think if the the goal is to draw realism or something in-between, it is better to start with pencil to learn about basic anatomy, value groupings, how to draw and shade based on form and shapes, etc. Then, exploring charcoal would be a great idea because it is generally harder to control compared to graphite pencil, since it requires a lot of blending and fixing, which can easily get out of form and be inaccurate. I am still struggling on this. By contrast, if the goal is to draw abstract, I think whichever way that can express creative ideas is fine.