I went from ground zero to professional within a little more than 3 years. I would trace a comic cover I liked, then I tried drawing it again from memory, then i traced it, then I copied it again and finally drew from memory again. Once i was able to mimic the comic art I learned about people doing master studies, so I started copying master works in grayscale then color. After that I started getting into local workshops and figure drawing classes sponsored through the local community college to learn about why muscles were moving certain ways or why a pose looked like the model but didnt look interesting at all... I finally came across rules of composition; like rhythm, direction, focus, color etc and it all finally clicked. I now prefer to draw from imagination when im just tooling around but I still use reference to take a pose from one source, lighting and colors from another etc so i can build and ship out art quickly.

We will all have our own path, I chose to learn off the art I enjoyed and then found out I enjoy doing most all styles once i had that confident bedrock down.

Best of luck, its a skill you can use in alot of careers, especially if you want to be self employed