If I get a job within the university, do I need to look for another job outside in New Zealand?

No, you do not need to look for another job outside if you secure a job within your university.

On-campus jobs offer convenience, relevant experience, and networking opportunities. If your university job fits your interests and schedule, and meets your financial or career goals, there is no requirement to seek additional work elsewhere.

As an international student in New Zealand, you can work up to 25 hours per week during academic terms, whether on-campus or off-campus. You may choose to balance both if you want broader experience or higher pay, but it is not mandatory.