It never ceases to amaze me when a prospective writer confesses that he or she has never put anything down on paper.
Obviously, that's the first step.
Just dreaming about it won't make it happen.
Anyone can write.
But not everyone writes well.
Shaping a manuscript as most everyone knows can be compared to shaping a formless lump of matter into a work of art.
But it has to be shaped and chiseled more than once; sometimes you might even have to start over, and, when it reaches its final stages, it still might need a trim here and there.
Without the benefit of an objective reading, you might consider taping your manuscript.
When you listen to it, it's like hearing someone else's work and you can edit out the hiccups.
The best test, however, is reading one's work in front of an audience, whether a roomful of people or one person; you can feel it when the listener loses interest or when the rhythm is off or when you've used the wrong word.
It's a good way to stand back and look at your work objectively.
It's important to have the necessary materials and tools to do the job if you want to be a writer.
You can't create anything from a formless lump if you don't have something malleable to work with in the first place.
The tools you need as a writer are a collection of words on paper, a story outline, a typewriter or word processor, and a few books offering guidelines on how to prepare a manuscript.
Then, you keep doing it till you get it right.