Hi Ashley,
It's indeed a very great question. I'm not sure what does your product do to give you the right answer but however based on my experiences working for a product with so much diversity in the users, I usually choose to focus on some personas first, the one that will be my main users in the next release, or the first MVP, depends on my product roadmap and strategy.
We can tackle their problems first and put the other personas, pain points, needs or objectives in backlog, after some releases we can have a look and add more personas to expand the product features, usually these are the variation or use cases and we tried to build features around to improve or solve these different use cases.
There are of course a lot more to discuss, let me know if there is still concerns.