A few weeks ago I tried running Linux for the first time and it was...an experience. Everything kind of clicked. I keep trying to learn more, and I think I'd like to work with Linux if I can. Unfortunately for me, I've been a bit aimless in my life. I am no longer a high school freshman, or even a college freshman, and at 30 have no real career to speak of, and no professional experience in IT or even IT adjacent fields.

My question: what is the most efficient route to a fulfilling job involving Linux for someone without an IT/CS background?

I have considered going back to school for a computer science degree, but that would be a huge debt burden, in addition to four years of lost salary (not that I have much of one right now, but never the less). Still, I haven't entirely ruled it out.

I know there are more specialized degrees/certificates, but I'm not sure what to look for in that department.

At this point, I feel like I don't even know how to begin looking. So I guess this question isn't really about finding a complete solution (though that would be very nice if it came up), but finding the tools to start out with.

Well, if you are sure ..

There are (loosely) 4 main tracks:
SysAdmin
Database Admin
Network Admin
Programming (split into front end ie web/GUI, or back end)

You would want to think about specialising in one of those, as even one has a huge amt to learn (although knowing at least the basics of all is more or less reqd, at least for experienced guys).

I'd also recommend concentrating on the Linux distro that is most reqd for jobs in your area.
Normally that would be RHEL or a derivative eg Centos.

This is a an oldie but goldie intro tutorial http://rute.2038bug.com/index.html.gz
See also www.linuxtopia.org for loads of free to read manuals.

HTH & Welcome to LQ

Well first, welcome to GNU/Linux and welcome LQ! About time you got here!

I would not think about certifications, and truthfully, they are not generally worth much in the job marketplace in my own experience.

The ONLY thing that you can sell is your particular combination of knowledge, skills, enthusiasm and personality!

From your well asked and written question I'd say that you are on solid ground in the personal traits department.

Knowledge, you are getting, and getting it on your own initiative counts double! The absolute best way to build your knowledge and transform that to skills is by hands-on experience. And the great thing about GNU/Linux is that you can get all the hands-on you are willing to dedicate time to, at no cost for the software!

So the best place to start for getting and learning the tools is to set up a running instance or two of GNU/Linux on whatever hardware you have available. Don't allow games, glitzy GUIs and over-clever experts to distract you - just learn the basics and learn them well.

Learn about the Unix heritage of Linux and learn why it is important!
Learn the underlying philosophy of *nix - text-in, text-out, pipes, ownerships and permissions. Everything else follows from that!
Learn to use a console based editor well (Vi/Vim is my recommendation, but master at least one).
Learn your way around the man pages - how to read them and how to find by topic.
Learn basic regular-expressions and the built-in tools present in all *nixes, grep, sed, awk, cut, sort, uniq, ps, top, etc., etc... One will inevitably lead you to the next!

All of that is pretty much universal and free! With a little dedication to learning it, you can build some useful, saleable skills just from that in a matter of days to weeks. Also, organize your tasks and resources as if it were already your job! Those skills will translate directly into value that you can sell!

Ask good questions here at LQ and you will learn more than just those answers too! You will learn the vocabulary, maybe a little humor, and good interaction skills common to an IT environment as a by-product!

When it comes to selling those new skills (aka finding a job), use that same initiative and enthusiasm! You won't find "My perfect job!" listed in the classifieds. Knock on a few doors, make some calls, make yourself known, see what falls into your lap!

And good luck!

Another good way to learn is to read other qns/answers here and also try to come up with your own answers.
Doesn't actually matter if you do; just trying will teach you lots