What kind of writing? I'm a fiction writer; I mostly write fantasy. My goal in life is to become a published, professional novelist.
No, I didn't go to college to be a writer. I did take one English class that was about fiction writing (genre fiction) but mainly because I needed more credits and it sounded like fun.
I started writing as a kid. As a teenager I joined a fanfiction club and write fanfics. That's mostly what I wrote for about a decade. They say you have a million words of crap in you before the good stuff comes out and I think I got at least a million words out writing fanfic.
Then one year some buddies from one of my fanfic clubs and I joined NaNoWriMo and we spent a month writing novels and egging each other on. Some friends in another group had gotten involved with a serious writing workshop, so I submitted my novel and was admitted to the workshop the next year. That was in late 2002 and since then I've mostly been trying to write fiction seriously, no more fanfic, just marketable stuff. I joined a weekly critique group which I have been attending for about 5 years. Through the workshop and the crit group I developed a network of friends with similar goals, most of whom have now sold novels or at least several short stories to professional publishers. I sold my first story to a pro market in the spring and am trying to finish the 3rd draft of my 3rd novel so I can market it to book agents. I submitted the novel to a respectable literary contest earlier this year and just found out it took 2nd place in my category, which is awesome because one of the "prizes" was a party with book agents who were actually eager to talk to us winners.
I suppose it depends on what you're writing but most of the writers I know didn't take college classes, though many do occasionally attend workshops or retreats. Since my circle is composed mostly of SF/F writers, most also go to writing-related panels at science fiction conventions.