I'm not sure that I completely follow what you are asking.. see if this helps
If you want to navigate to a different app, you pull up from the bottom of the screen and hesitate. It will tile your open apps, at which time you can tap on the one you want to switch to.. or you can swipe up and kill the app.
With some practice you can can pretty quickly switch between adjacent apps by swiping up, over and back down
Switch between apps on iPhone - Apple Support
the home button method is for iPhones that use Touch ID. If your details are correct and you have an XR, that's a Face ID phone with no home button.
to navigate within an app, the app has to be designed to allow you to return to a previous screen. This is typically accomplished with a symbol like this <
If a certain app you are using doesn't have these features, it's not an 'Apple' thing. You could reach out to the app developer and suggest a feature or inquire about navigation within their app
How to contact an app developer - Apple Support