The transition from amateur photographer to pro is one of the hardest to do since we need to start treating photography as a rentable career and not just as a hobby that we love.
In the beginning, most people don't start making a considerable amount of money out of it, but I would say persistence and consistency are the keys.
With practice comes perfection, and perfection is not the same for all people, so it is essential to know what it means to you since it depends on your style. Ones you have a style and the basic knowledge of photography (light/composition/post-production) than the hard work begins.
The bad news is that there are no short cuts; every day is going to be a learning process when you are starting. One toll that is underestimated is how the internet is fantastic to showcase your work and thoughts but beware that you are going to receive all types of feedback. With this in mind, not everyone is going to resonate with your style of work, so it's essential to learn how to deal with negative feedback.
My last thought on this subject would be that the world of photography is vastly competitive. However, if you persist in the path of learning your craft, with passion and time, you are going to start getting more projects that resonate with you, leaping a passionate hobby to a rentable career.