Depending on who you ask, writing is either an arduous craft that takes years to develop, or something anyone with a keyboard can easily turn into a million-dollar enterprise. As it is with most controversies, so it is with writing: both sides are wrong.
Yes, you can start writing right now, and there are plenty of venues for doing so. Free web sites like Blogger.com will let you get started without even so much as an investment in a domain name. But unless you're an unusually gifted writer, you shouldn't worry too much about the risk that ladies will swoon over the stark beauty of your prose after a few minutes' work on your part.
The good news is that you don't have to be an off-the-cuff Chaucer stopwatches online or an out-of-the-box Hemingway. Writing is a skill that improves with time if you apply a few basic principles.
Write Something Every Day There is something about writing that makes writing easier. I can't tell you what it is, but I can tell you that when I'm writing a lot, I find it easier to write even more. Ideas take shape. Connections form.
Writing is One Step, Editing Is Another In general, your writing direction should be forward. Writing quickly helps you avoid the inner editor, who otherwise would want to wreak havoc on your brilliant ideas (that's just the kind of person your inner editor is). This is not to say you can't occasionally move back if you find a fatal phrase that simply cannot stand as it is, but make it a rule to try to save most of your edits until the end. Tell your inner editor you'll be happy to let him come out to work just as soon as you're finished playing.