Quiz settings in Moodle control many things such as:
Directions about the quiz.
When the quiz will be open and when it will close.
Any time limit for the quiz.
The number of attempts allowed.
The scoring method of multiple attempts.
If the question order will be randomized.
A quiz can be configured and saved without having any questions in it, but it should be hidden from students until it is complete (see Manually Hide a Quiz Link and Quiz). The quiz can be made visible to students after the quiz is completely set up including:
Layout of questions
Points of the questions
Score for the test
Note: In general, you should not edit quiz settings after students have started to take the quiz. Two exceptions to this are:
You can safely extend the Close the quiz date and/or time, or uncheck the Close the quiz option entirely.
You can increase the number of Attempts allowed under the Grade section.
Editing a quiz
Go to the course homepage and click Turn editing on.
Find the Quiz you want to modify.
Click the Edit menu to the right of the quiz.
Choose Edit Settings.
Make your changes to the quiz settings.
Click Save and return to course or Save and display.