I see a lot of people recommending things that a beginner definitely isn't going to find fun. It's not fun to bang your head against problems before you even understand what is going on. If that sounds like you then you do not want to be touching anything like Rust, C, C++, etc. Some people are recommending Python. I strongly recommend against that. Yeah it's a simple language, but it breaks all conventions that other languages have set up. Whitespace, tooling, comprehensions. They're all different. You'll struggle with the terrible tooling, the whitespace syntax isn't used in any other popular languages, and the stuff that is in other languages is implemented completely differently.

I like Ruby for fun. It's an incredibly approachable language, it's extremely fun. The tooling is dead simple and works on every system out of the box. Of course everyone else in here is gonna recommend other different stuff, but I can tell you that I have developed professionally with both Ruby and Python for over a decade and the people suggesting Python have most likely not programmed with many other languages.

I'll give a second suggestion. I recently started learning Unity and it was a blast. It brought back that joy of programming for me. Of course, most of it isn't programming, but that might help things in your case. So maybe if you're looking for something that isn't so ... 'backend' then that might be what you want, a video game engine that can get you started easily.

Some others suggested esoteric or less used languages like Lisp or Forth, and I can't give any recommendations about those. Maybe you'll have fun with those, maybe you won't.

Finally, one last thing, you can compare a lot of languages to see what 'equivalents' would be with this tool. https://evmorov.github.io/lang-compare/ruby-python/ There's also https://codethesaur.us/, but it covers different bits and doesn't seem to have much for Ruby.