Ruby is my first programming language (that I stuck to and learned all the way through). This is because it was the easiest language to pick up. I learned Ruby through O'Reilly books, but I'm sure you could find YouTube tutorials as well:

Python on the other hand, is widely used, but I hate how people's code is broken if you don't use the exact version of Python they used to program it. It does force you to learn proper coding practices though like keeping your spacing aligned in such a way where the code is easy to read (although languages that don't force you to do this allow you to use tab or double space whereas Python forces you to use double space) Python also interpretes to bytecode whereas Ruby interprets to C (Well cruby interprets to c, but we also have jruby and so on and so forth) which means you can use Sorbet and LLVM to bring your Ruby code to native C and compile it all. Ruby has threads and ruby on rails and metasploit is written in ruby (and python). The glimmer gem means you can write GUIs in Ruby.

Okay okay enough shilling my first language, whatever language you choose to learn, get on repl.it and https://www.codewars.com/ in order to challenge yourself and sharpen your programming skills.