That is pretty much what I am doing these days. I have made one drawing and I'm frequently changing it, then uploading them to see what gets attention. Either practice and persistence will pay off, or I will completely [----] lose it.
I have already studied, taken a few courses and researched in art and advertising, along with just browsing popular art. Can't go to school, as there is nothing local and I'm not willing to move away and live on student loans for a few years. Have no idea and never heard of online/remote courses being any good or successful. Even then, there is the student loan dept and the risk the course I took was of no help. If only I knew of some alternative, other than pestering people into giving me help/guidance/constructive criticism.
All I can do is keep trying. Don't know what else to do.
PS: Yes, I know, don't worry about popularity. I have already gone through that. There will still be art that I want to do just for fun. However, there is also art that I want to do with a "purpose". Think of it like doing art for Play & art for Work. It is one thing to make a game and have fun with it, it is another thing to make a game and have fun with it, but also have an adequate customer base that also finds it fun. Otherwise, it will be a waste of time and money, be canceled and possibly be fired/laid off. That is the best analogy I could come up with.