Drawing for fun is mandatory
There's something I've found myself having to say a great deal over the last few years, so at this point I think that it's critical that I state it here, and equally critical that you understand. As such, I've separated this out into its own page to give you the best chances of actually reading this.
You should not be devoting every moment you spend drawing to your growth as an artist.
Too many students think that the only way they'll get good is if they do nothing but practice, and they feel that any time spent drawing but not doing exercises is time wasted. This is simply not true, and more than that, it's extremely harmful. I recommend that of all the time you spend drawing, you only spend half of that on improving - however that may be. Whether it's working through Drawabox, some other course, or even just doing structured studies of your own.
The other half should be dedicated to drawing for the sake of drawing. You've likely gone into this endeavor for a reason, and unless you pursue that goal throughout, you risk losing grip on it. That means trying to draw those characters, vehicles, props, clothes, cultures, worlds you love now, whether you feel you're ready or not. And no, you won't be ready at first, and you won't be ready for a long time - but it doesn't matter.
Don't get caught up on whether or not you're ready. Focus on what you'd draw if you were the most proficient artist in the world, then draw that. Poorly. Use whatever tools you feel like using. Whether you're actually having fun or not, the main focus here is drawing without having to worry about that time actually improving your skills in any way.
Sure, if you grind your studies every moment you can spare and you somehow manage not to burn out along the way, you'll come out with considerable technical skill. You'll also have no idea of how to apply it - and as many will tell you, facing that reality and overcoming it is perhaps more difficult than learning to draw in the first place.