If you're looking to get into urban planning I can tell you that your undergrad is not that important. I did my undergrad in geography which is a typical route and it was helpful in some aspects but I wouldn't say it was necessary. In my masters cohort we had people with degrees in psychology, business, art history, philosophy, ect. and a couple architects from India.

A lot of degrees are useful to urban planning, even if they aren't the typical route. It's really about how you apply that degree and understanding to the field. Philosophy and sociology are good for the policy part, business is good for the finance and economic part, ect.

Working for a city can be challenging especially if you have aspirations and want to see real change, something that was drilled into my cohort in school but took a couple years in the field for some people to figure out. Maybe non profit or a private company aligned to your values might be a better route than public of you're looking to get into something adjacent to public planning. That being said, just being an active member in your community and speaking up for projects you believe in at council meetings is more impactful than writing the policy.