The first thing you need to do to become a writer is learn the rules of writing. Everyone should know that any piece of writing has a beginning, middle an ending.
Step2
In order to be successful at writing, you should take some classes. Buy a grammar book to improve your grammar. Have a dictionary handy, too.
Step3
Make sure you have the passion and talent to pursue a writing career.
Step4
Good luck!
Tips & Warnings
Take your time on writing, don't rush. You don't want to mess up.
Don't copy someone else writing. Come up with your own material and writing.