I know many folks are using Hot Potatoes and all, but Moodle has a fine quiz module of its own. If you are going to build a bank of quiz material, you might as well leave it in-house! Also, if you have old Blackboard quizzes, Moodlers have successfully imported them into Moodle before.
Why don't you play with the quiz module a little and then with the lesson module, before you start thinking about learning two different systems (Moodle and Hot Potatoes) at the same time?
Feel free to ask questions about anything here. A number of us will try to keep track of you here.
I think you are experiencing seasonal traffic. Many Moodlers started at the beginning of the academic year--back then there were plenty of fundamental questions. These days there seems to be a lot of development work flying around.
What I hope to do is each week post a drill or quiz on whatever grammatical feature we're doing, and let the students re-take it as many times as they want, until they get at least 90%. Ideally the questions would be a random selection from a pool, but at least they should be randomly ordered. Can I do that? How?
This can be done pretty simply. Create a Moodle Quiz, make sure that you leave the default as "unlimited attempts." You can choose a "shuffle" to arrange the questions randomly for each student.
Once you are finished with the settings page of the quiz, you will go to a page called "Editing Quiz." First, create some categories of questions. (You may choose categories like 'difficult conjugations' or 'easy conjugations'. You may choose different categories for kinds of vocab "restaurant vocab" or "hospital vocab," etc..)
After you have saved your work with categories, return to the "Editing Quiz" page, and choose a category from the pull-down menu and start creating questions.
Make as many as you want in as many categories as you want. These questions will be your "bank" of questions. You can use the questions individually (on this quiz or any quiz you ever wish to create), or you can randomly draw from them. Sounds to me like you are most interested in the random aspect...so...
For each category, create a special "type" of question called "random set," point it towards a specific category. Whenever you add this particular "random set" question to a quiz, it will randomly choose a question from the category that you've identified. You are in charge of the variety, based on how many questions you create for each category.
Now, after you've created all of the potential quiz questions within their various categories and after you have created a special type of "random set" question for each of your categories, you should "select" questions from the right side of the screen (toggle the check box) and then "add selected to the quiz".
Now be sure to save the quiz and return to your course page. This should do the trick.