I've always taken the approach to decide on a new concentration to study, and then learn the languages appropriate for that. First time I did this, the concentration was databases, so I set about learning SQL and data design and relational algebra. I wanted to learn more about front end development, so I focused on JavaScript, DOM, and single page applications. Other examples abound. But having a distinct idea of an application I want to build before learning a particular language has always worked out better for me than trying to find an application after reading a language's documentation.