Writing does not have to be a career thing, but one can spend one hour on it a day or so.
With a little background in some subject or occupation, one can use that experience and knowledge and build up a file of pieces that one may submit for publication.
Mine is simply reading and thinking about the Bible, which has led to devotional writing. My intention in reading the Bible wasn’t for fame, though.
We all have reasons for doing what we do, so use that experience and knowledge one gathers in the course of doing one’s thing and build up a portfolio of writings.
It may be on a subject or two or three, depending on the person and their level of knowledge and experience in each subject.
Opinion articles can be great for starting out if one is still gathering knowledge and experience in a field or two.
Before one writes, one needs the know-how of writing, and the details of how-to-do the tricky parts. Better to know before you go.
Then, write for about an hour a day or so, and build up a body of work, for self-publishing or traditional publishing.
However, writing for the sake of it may feel empty, if one does get that way, consider the why. Why do you want to write these articles? Is there a point? What’s one’s purpose?