Hello Ed,
If you are new to Moodle, I suggest you start by familiarizing yourself with the different types of questions. Then, depending on what you want to do, you may want to use random questions ↗, the calculated question ↗ or the formulas question ↗.
As for random quizzes, I think there is no new development. Rick's suggestion above ↗ using random groups may be a suitable workaround for you.