If your goal is to obtain a staff job at a publication or with a publisher, a college degree is a near must. Creative writing programs, too, can be extremely valuable; they force you to write and they include regular criticism by professors and peers. On the other hand, the habits (and even rules) learned while writing for an academic degree may have to be broken before you can produce a salable book or magazine article.
Most creative writers—those with MFA degrees and without—claim that experience trumps education, as nothing can be a substitute for experience. As Virgil said, “Trust one who has gone through it.” But even if you live a rather humdrum existence, you can usually find material for your writing simply by exercising your imagination. Emily Dickinson, for example, created perceptive poetry though her lifestyle was, by most modern standards, frightfully dull.