I don't think you'll get Word to do that. (What the hell is so great about Vancouver?!? Why not make life easy and use one of the installed styles?) Anyway, some Googling found this: http://www.citethisforme.com/vancouver
You're on your own from here, kiddo. (hey, and well-raised humans upvote folks who answer their reddit questions...)
I mean, you already bought the key, but just so you know you they still sell retail versions of office, but it is more expensive https://www.amazon.com/Microsoft-Student-One-time-purchase-Download/dp/B09H7GPR1G/
If you are always online, I think their free online office is good enough for basic word processing, and Google Docs is free and very capable as well, and there are alternatives like LibreOffice as well.