Don't want to be a writer. Instead, want to write a story (or a poem or a play....). Have a definite goal in mind instead of a vague yearning to have the glamorous lifestyle of a writer (by the way, I just hauled the garbage out to the curb).
I'm going to assume you want to write fiction. That means, in all likelihood, that you read a considerable amount of fiction. So - what do you want to write?
If you're just beginning, then write the kind of fiction you like to read. Don't steal it - don't imitate someone else's plot or use someone else's characters. Write in the same genre, though. If you like science fiction, work on a science-fiction story; if you like historical romance, work on one of those; if you like sexy vampires, take to collecting coins or driving race cars instead. We have too many of those already.
Study the best of the genre you've chosen. Re-read your favorites, but this time read critically and note how the writers hook you in, what makes their styles and characters so engaging, how they pace and plot out a story.
Once again, you are not copying substance; however, you may pick up pointers and learn to imitate an approach, an attitude, or a style. Don't worry about that at the outset, because as time goes on, you will develop your own individual style.
But do your homework. You don't want to reinvent the wheel, so study those favorite works of yours and learn from them. This time around, you're not reading for enjoyment, but for inspiration, for insight, and for enlightenment.
Then when you work on your own story, you're not starting at the bottom, but standing on the shoulders of the writers you most admire.