There are people who want to be writers and those who must write. They are not always the same people. When someone asks, "Should I be a writer?" the answer is No. Not if you have to ask.
How do you write? is a harder question. That one has no answer. Not even a multiple choice. I might say, "No outline. No blueprint." But that answer would be a bum steer: Many successful practitioners work from outlines and know exactly where they're going before they hit the word processor.
I might say, "Never go to the word processor till you've put the story down in your first flush of inspiration, preferably with a free-flowing pen on yellow-pad paper." Later I transpose it, using the processor more for editing than composing. This is the wrong answer for a colleague who writes like he's building a tile floor one piece at a time, set and polished, till he comes up at the end with a ready-to-publish story.
I think you've got to have an idea or a character that carries you like a surfer's wave. I also think you start your writing career by adopting the form or style or voice of an admired writer who is accessible enough to be imitated. Gradually you become yourself.
Finally I would tell you to ignore the advice I read recently in a magazine for writers: A writer should be prepared to tell his story to the editor in three sentences (or was it three words?). If you can't do that, says the editor, don't even bother to submit the work. Boy, do I disagree! If you can tell your story in three sentences, why write it?
I write like a painter, going over the story draft after draft, adding color, changing shape, bringing in light and shadows (chiaroscuro, to labor the metaphor). A dab here, a highlight there, a new insight and, of course, constant wipeouts of segments that don't belong. All these brush strokes, all these layers, all these drafts. All this time. Three sentences? Uh uh.