Lots of articles on here on how to create effective SEO pages - and glad to see you’re diving in my friend!
In terms of architecture in the backend, you want to use the assign to main page -
In this example - “Horne Lake” is a sub page of Central Vancouver Island (which is a main page)
Personally, I don’t really care about the nested URL’s in terms of structure (vs a flat structure) and it does not have an impact on the ability for those pages to rank (Google doesn’t rank you better with nested URL’s)
This is the subpage for instance Horne Lake Real Estate For Sale | Central Vancouver Island Real Estate (note not nested even though it’s a subpage) - ranks top 3 for local searches and according to search console.
