The answer isn’t simple. There is an infinite amount of knowledge you can learn about writing by reading books and reading writing blogs. There’s no writer who ‘knows it all’, there’s always more to learn.
“The most original thing a writer can do is write like himself. It is also his most difficult task.” -Robertson Davies
Famous writers weren’t born good writers. You have to find your passion, and exercise it so that you can spring forward your talent. The more you read, the more you write, whether abstract or focused, you get better at writing. Secondly, you don’t get good at writing overnight. Start young if you can. Once you become a writer, you can never fully quit.
“I’m either going to be a writer or a bum.” -Carl Sandburg
Everything you learn about is based on writing, stick to one class of writing at first, get good at it, and stick with it.