A little background: Through my teens in the 90's I did a lot of the things you may expect. I was a script kiddie on mIRC, made a tank game in Unreal Engine, and did some Quake modding. From 2002-2004 I landed a job doing Java web dev, SQL, and overall database administration because my father's friend needed someone that could do that. I was ok at the job, but not great. Being young, my hobby that turned into a 9-5 made me want to stab my eyes out and I quit.
With that said, I can understand a lot of what's going on, but it doesn't "click" anymore. I spent 20 years as a career machinist, but I physically can't do that anymore. Here's the rub - my twin brother is a brittle diabetic and can't work (lots of other stuff going on as well), and our mother is getting old (father passed this year). The only reasonable way forward that I can see in order to be able to support my brother is trying to get back into development.
When I stopped, subversion was what we used. I'm trying to understand Git, but it's a giant conceptual leap. I guess, what I'd like to hear from you all is a way to jump back in as quickly as possible in such a way that it may be a career.
Thanks
My personal recommendation:
Pick up Python, it's easy to learn and highly productive. If you also learn fastAPI, you can benefit from highly validated, declarative models to build REST APIs in the backend, well fast. It will yield quick results, you won't become demotivated and you can pick up a paid project soon.
Pick up Rust. It's "in" right now and I get requests from marketing people that know nothing about programming, asking if their project could be implemented in Rust
Go with memorizing the shell commands first, try to understand git later. Get productive, try to get where you were with e. g. svn or cvs. If you are comfortable, look at something in depth if you have a problem that you can't solve with the knowledge you have.
Fuck Java, seriously.
You have commercial interests, so it is probably wise to look into becoming a fullstack dev to maximize the kind of projects you can do. Look into React, vue.js, svelte. React is probably still the most widely used framework, you'll quickly do a project with vue.js and svelte is a super interesting look into things to come.
Toxic...
You can find a lot of good work doing Java.
Java have had very bad press lately (since the log4j fiasco I guess? maybe since before).
IDK why people blame Java for any issues with any library/project written in it... it's as dumb as blaming C/C++ for all the windows fuckups, and nobody blames php for the various cpanel vulnerabilities or python for all the shit people write in it.