I used to do a little SEO and content type stuff, but that was back in the 2010-2011'ish time period.
The hardest part was trying to write to computer-generated titles, which frequently made absolutely no sense, or were often pretty stupid if you tried it in reality ("How to Build a Rabbit Hutch Out of Wire Shelves"), or trying to write something super-nichey with a serious face. ("How to Make Forensic Science Trading Cards".) Out of the clear/useful titles, you had to come up with a fresh way of explaining things, so that it wouldn't get rejected for "matching existing content elsewhere" (ie, suspicions of plagiarism). For example, I wrote one article about how to make a javascript calendar and another about how to expand/collapse text on a web page, but both got flagged by the system and had to be manually reviewed to make sure I wasn't just copy-pasta'ing someone else's work.
I made okay pizza money on places like Demand, but ultimately quit, because I felt like I was doing the equivalent of cluttering up the Internet search results with junk articles, and it was hard to get in and snag the decent titles before someone else did, and it was annoying to sift through pages' worth of writing prompts that no one in their right mind would want to write in order to find one or two that caught my interest.
After Demand shut down, I tried a few times to get back into it, doing stuff like writing product descriptions for sites, or running searches on key words and typing in the top results that would come back, or transcribing audio into text. But those didn't pay nearly as well as the junky articles, and so I abandoned that, too.
Perhaps the current landscape is more profitable/more entry-level-friendly? What two or three places were you thinking about trying out? Give them a go, and tell us how they look after a few months.