You have prepared a quiz exam for your students. It is currently in a hidden state. The exam opens on the day of the exam, at a time that the students know about. However, to satisfy yourself that it is doable in the time allotted, You wish to do a dry run yourself before that date. How can You accomplish this?
Method 1: Use the Preview feature available to you as a teacher as you are making the quiz.
Method 2:
Step 1: Make a dummy account with a name like "Test Student".
Step 2: Enroll that user in the course as a student.
Step 3: Add a "User override" to the quiz, so "Test Student" can attempt the quiz before it is open to everyone else.
Step 4: Log in as "Test student".
Step 5: Attempt the quiz.
Step 6: Log back in as teacher.
Step 7: Review the attempt.
Step 8: Go to Results -> Grades and delete the test attempt.
Step 9: Unenroll "Test Student" from your course.
Method 3: Set up a Moodle Playground course for your teachers. Add teachers with dual role (teacher and student). Teachers can later copy the quiz/assignment/whatever over to their live class.