The Certificate of Proficiency (Undergraduate) is not a formal qualification. You should only apply for this certificate if you are intending to only complete one or two undergraduate courses. For example, these may be interest courses or you may want to study them to prepare you for studying another qualification in the future. Alternatively, if you are studying a qualification at another university, you may want to study a course at Massey to credit back to your qualification.
You will need to meet the entry requirements for the courses you choose.