Hey there! I do coding for a living, and here’s my 2 cents:
Languages like Ruby (with or without Rails) are seldom used in the job market, unfortunately. While it’s much more modern and expandable than traditional languages, most companies just haven’t had the time or resources to make the switch. It’d put you far ahead of the game to learn Ruby now, so when companies do finally swap to something else, you have years of experience under your belt. Fortunately, a lot of coding concepts you learn in Ruby translate easily to other languages.
However, there’s been a huge push in Devops for many organizations, since frequent patching is becoming the norm for software. Most Devops tools are built around Python, so it works very well with applications built in Python.
A large portion of new applications are moving to a web-based platform. Apache, Django, NodeJS, and a few others are super common for hosting. AWS is also a nice tool for modern applications, as it keeps you from having to maintain your own hardware.
Additionally, a lot of web back-end is comprised of C# and custom APIs. Front-end is usually HTML5/CSS3.
What I would suggest is learning the following languages, which all build upon each other and give you exposure to each stage of the development process:
Python3
C#/Java
Powershell/Bash/Perl
HTML5/CSS3
SQL/NoSQL
These will cover about 80% of the job market at the moment, at all stages.
I know quite a few of these languages, so if you ever want some 1-on-1 teaching, I’ll be happy to meet up at the Makerspace!