In the upper menu, go to the Quizzes tab, then click on the Add new Quiz button found here.
You can add content in the first section, or skip to the Quiz Questions section where you can add existing questions to your quiz. You can click on the + icon, drag and drop and search for specific questions.
On the right hand side menu we have the option to place this quiz into a Quiz Categories. To create a new category, simply click on +Add new quiz category, type in the name then click on it add again.
When you are done editing, simply click on the Publish button found on the right hand side menu.
You can also access the Special Settings page where you have some useful options you can further tweak.