Hi Pam,
So far as I know, Questionnaire does not support randomization of items in the question. And in this case, I am assume you mean randomize the order of the possible answers.
If that is what you want, you might be able to achieve it by using a quiz and shuffle the answers to each question.
If you mean to randomly pick which question to use, so far as I know questionnaire does not support that. Neither does the Feedback activity, however with it you can set it to alter which questions are shown based on a previous answer. Quiz does support randomly picking which questions to use.
If you give an example of your question(s) we might be able to give a better/different answer.