The only way to randomize the order of questions in a Canvas quiz is to create one with questions drawn from the question bank containing the questions.
In order to do this, the questions must already be in a Canvas question bank.
However, you may either inherit a quiz for which there is no corresponding bank (as is the case with this practice quiz) or have created a quiz manually in Canvas which will not generate a corresponding bank.
There is a three-part workaround for this: export the quiz, import it back in as a question bank, and create a new quiz drawing questions from the question bank. This sounds complex, but it goes pretty quickly as explained in this four-minute clip.