I'd also suggest picking up a copy of Writer's Market 2017. It's a great guide to different markets, publications within those markets (including trade journals!), and what each outlet looks for from freelancers.
I'm also a huge fan of The Essential Guide to Freelance Writing, which offers tips for crafting pitches, finding the appropriate outlets, and contacting the right person at each place. It's really approachable, and the author offers some quality "real world" expertise.
Thanks a lot this was helpful! Is this the kind of book you own? https://www.amazon.com/Writers-Market-2017-Trusted-Published/dp/1440347735