Wow, I would venture to guess that there are entire books written to answer this one question! And I'm sure you'll find and read many of them in the near future. However, I'd like to focus on a couple of principles to consider along with some resources you may find helpful. Since this is a freelancing forum and you mentioned freelancing, my answer doesn't really address getting hired by a company - although it may possibly lead to just that.
Seth Godin is a familiar name in the business and publishing world. His advice to entrepreneurs is to 'pick yourself'. The meaning of this phrase boils down to not waiting for someone else to hire you or validate your ideas, but rather to act on them yourself. So look in the mirror and say "You're hired!". Now, get to work and start writing. Find a large enough audience and those publishers will be the ones jumping up and down screaming "pick me! pick me!".
The World Of Publishing
The same Seth Godin has also been heralding (and experimenting with) the changes that have occurred in publishing and brought on by the internet. The new buzzword is 'digital media'. One of the greatest reasons to 'pick yourself' and begin your journalistic aspirations immediately is the low barrier to entry. You can start writing and sharing your work with little to no upfront costs at all. But it does require formulating a plan followed by lots of effort. The old way of marketing through agents and publishers are quickly fading. Self-publishing is flourishing.
-Find Your Niche. I would say that before you do anything, the first decision you should make is to pick a category or niche that you will focus on. Some examples would be politics, sports, religion, technology, travel, finances, etc. Choose something that you are passionate about. Chances are that you will already have some knowledge and experience in this area that will help to establish your credibility early on. If not, then start doing some research, get your hands dirty, and write about that. Choosing a niche early on will also help you focus on the outlets you would like to contribute to - and ultimately form a professional relationship with. Yes, get paid. Without getting into details, this will also help you with future SEO efforts and getting found in search results.
-Understand Your Revenue Stream. There are many ways an author can receive payment for his work. Just make sure that you are legally set up to get paid the way you choose to earn your income. Freelancers (Independent Contractors) are typically paid per piece, but it really depends on the terms of a Contract or Agreement. Self publishers can generate revenue from selling paid subscriptions, advertising space, or syndication. Many successful authors also receive income from affiliate marketing - however, be mindful about 'spam' and possible negative SEO consequences of affiliate links. Another source of revenue can come from print and ebook sales. Sites such as www.iuniverse.com, www.lulu.com, and www.amazon.com are some places available to self-publishers. Search Google using the term 'self publishing' for a wealth of resources.
-Focus On A Platform. Will you be primarily posting on your own site/blog, elswhere, or both? This decision will come a bit easier once you've thought through the ways you expect to draw some revenue from writing. Signing up for a free account on WordPress.com, Blogger(Google), or Medium.com is a great way to start publishing immediately. It's also important to make sure your platform is optimized for mobile devices.
-Share It On Social. Social media is your key marketing tool. Enlist your friends, family, and professional colleagues on Google+, Facebook, LinkedIN, and Twitter to help you get the word out and share your work. The platform you choose to publish on should be able to integrate with most major social media accounts.
-Fail, Fail Again. Author and business coach John Maxwell wrote a book called Failing Forward. The main idea was learning from our failures and mistakes in order to succeed. Write, post, and publish. Write for the love and joy of it. Be consistent and post on a regular basis. Grow a thick skin then get constructive feedback in order to hone your craft and develop your style. In the end, good writing is about making that connection with your audience.
Hopefully this provides some direction and clarity for you.