The Quizzes help pages are structured into three categories: Essentials, Advanced, and Troubleshooting (see topics listed under Quizzes on the menu to the left). Essential topics are the fundamentals that an instructor needs to know and use to build a basic quiz. Advanced topics go into more depth and detail. Advanced topics assume familiarity and understanding of the essential topics. Troubleshooting...well, that category speaks for itself.
Note: Under essentials are two subcategories: questions and quizzes. That's because the Quizzes tool is two tools in one. It contains a Question Library, where you build and store questions that you can import into any quiz, survey, or self-assessment, and a Quizzes page where you build and administer your quizzes.