Learn some JavaScript the fun way
JavaScript, which is completely unrelated to Java programming language, is the dynamic driving force of modern web pages. Most interactive stuff you see on the web is as a result of JavaScript code executing in your browser. Even major modern games are written in (HTML5 and) JavaScript, so you should know at least some of it.
Task
Learn about JavaScript and programming in general through these interactive tutorials:
Complete any of the tutorials and gain a lot of new knowledge!