A modern front-end stack looks like:
For structure/content: raw HTML, or less commonly a language that compiles to HTML (Haml, Jade, etc.).
If the HTML is being rendered and served from the backend, you might use a templating language like Django's templating or Jinja (Haml and Jade also have these features).
If you are creating an application that does a lot of AJAX, you will also often use a JavaScript templating system like Handlebars.
For styling: raw CSS, or fairly commonly a CSS pre-processor like SASS, Less, or Stylus. Very often you will use a CSS framework like Bootstrap or Foundation to give you pre-made forms, buttons, grids, and other essentials.
For logic/interaction: JavaScript. Many people will also use compile-to-JS languages like CoffeeScript, TypeScript, or ClojureScript (in decreasing order of frequency). There are a lot of libraries/frameworks that can be used here. Most commonly you'll use jQuery and jQuery UI widgets. For more complex applications, single page app frameworks like Backbone, Angular, or React come into play.
Build process: For more complex projects, build tools like Grunt or Gulp to watch for changes to the filesystem and re-compile files (typically when you're using CoffeeScript or a CSS preprocessor), to package everything for deployment (minifying JavaScript, etc), and to run tests.
Packaging: Often you'll use a tool to keep track of modules/packages. These tools are quite different. Bower, RequireJS, Browserify, Component, and other tools occupy this space.
Often you'll use Node's npm to keep track of build process and testing packages!
Testing: For testing you'll often see frameworks like Jasmine or Mocha/Chai for unit tests/integration tests. For end-to-end tests you might see things like Selenium (run tests in a browser window). There are also test-runner frameworks like Karma.
Debugging: Chrome's developer tools (or Firebug/Firefox/Safari).
For someone starting out this is probably overwhelming. The important things to realize are that:
1) No one uses all these tools
2) Most of these tools are only useful for large complex codebases with large teams.
2) The most common stack is raw HTML, raw CSS, raw JS, jQuery, jQuery UI, Bootstrap, no build process, no packaging, no testing.