What language you should learn really depends on your goals.
If your goal is to make a game as quickly as possible, choose a game engine and learn whatever language it uses. If you don't want to use a game engine, you can pick up a language like Python (with Pygame, for example) or Lua and make your game like that.
If you actually want to learn how to program, I'd actually recommend learning C. I know it's not commonly recommended for beginners (due to it being unforgiving at times), but C is a very small language to keep in one's head, and it requires learning how a lot of things that programmers of other languages take for grated work, such as hash tables and dynamic arrays (things that many more modern languages provide as built in features).
About the fact that you're using a Chromebook: if you are willing to learn how to use Linux, you can install Crostini; A virtual machine for Chrome OS which provides a terminal interface as well as a layer for graphical applications. You can install it by going to the settings and scrolling down the menu to the section labelled "Linux" and going through the guided installer. It's pretty slow unless you have a high end Chromebook (and most Chromebooks don't support OpenGL, let alone Vulkan), though, so don't expect to be able to run any kind of 3D game engine - but you can definitely make quite a respectable 2D game.