How to display different content on the same page using different URLS

Not sure if there’s a specific reason that you’d want to use query strings, but it sounds like maybe localization could cover your needs. That would allow for your content to be translated depending on the user’s location.

I don’t have too much experience with localization for WordPress specifically, but it looks like there’s a ton of options as far as plugins that handle localization. Here’s an article from one, TranslatePress, which explains the topic more in depth:

https://translatepress.com/wordpress-localization/

And the WordPress documentation on it:

https://developer.wordpress.org/apis/handbook/internationalization/localization/