I was reading through the open source list of game engines but I'm not familiar with any of them. Are there any you would recommend for someone new to game creation? Ruby and Python are the languages I'm most familiar with if that helps with your suggestions.

I'll throw my suggestion behind Godot with 2.1.4

It uses a custom scripting language that has similar syntax to python, and is probably the easiest to recommend open source engine at the current time. 

I am planning to use master branch of Godot, it is just awesome and makes game development a joy. I highly recommend it. My stack is:

* Godot 3
* Blender
* GIMP
* Audacity
* Debian :-)

Godot is indeed great!   Since you mentioned you know python you might also checkout pygame,  or if you want to build an HTML5 game you could check out phaser.js.