You study by reading and re-reading, by dismantling and seeing how a writer achieved certain effects. You study by taking apart scenes, chapters, sentences, words. You look at structure, language, characterization, and narrative. And of course you write. You write regularly and you write to learn.
Many novices have an aversion to rewriting, which is the first biggest mistake to make.
And doing this over and over until something great happens. You find the right voice, the right character to focus on, the right story. Even then you'll have to revise and refine, which is why good novels take so long to finish. It sounds hard and scary. But when it does work, when you hit upon the right voice, character, and story, you begin to get a taste of that feeling you had as a kid, reading those piles of books in your room.