Odds are, you will also discover that you are writing longer than fifteen minutes with no idea where the time went. That's called finding your flow. When you're in the flow you'll notice that when you re-read your work you not only don't cringe, you actually grin. Your long-term goal might be to have a novel published within 3 to 5 years. Your short-term goal might be to pen the outline and synopsis of your book and complete the first several chapters within boundaries of the coming year.
Every goal varies for every writer.
It certainly wouldn't hurt to pen Op-ed's and submit those in the process, and to flex your writing muscles at every given and publishable opportunity. And no matter what, don't tell yourself you can't write, and that you will never be published because you're just not good enough. The fact that you are reading this shows a keen interest and a certain sense of committment to yourself and your talent and that is vital. What you must do is to allow yourself to reach for your writing goals. Follow these steps and you will likely encounter success in one form or another.