When it comes to coding languages, the best advice (that's tough to follow) is to pick one and stick with it. If you flip between languages or try to learn more than one at a time, you'll quickly find yourself overwhelmed and unable to get past the initial roadblocks.
Javascript is a powerful scripting language that runs in browsers. With the creation of Node, people have begun running JavaScript on servers and using it to create "native" apps that run outside of browsers. Javascript has exploded in popularity over the last few years.
Python is a robust language with easy-to-learn syntax. It's used in many environments, from scripting to full-fledged apps and powerful data analysis.
Ruby is a minimal, beautiful language that's used extensively to make command-line tools and scripts. It also powers the extremely popular web application framework Rails.