How do I see what apps are open from the home screen without a home button

I understand what you’re asking. I thought you might find it useful to get the eBook version of the manual for future reference. It’s some 200 pages covering just about any iOS 13 usage question you’ll ever come up with.

Just got mine last night - I, however, got a tutorial on mine. To see the apps that are open, pull it half way up from the bottom and you'll recognize it.

Go into iBooks and search the store for iOS 13 and you will see the Apple iOS 13 guide free download. It will cover all devices capable of running iOS 13 including your 11 Pro.