Hi pgbrunswick,
You are very welcome, we’re happy to lend a hand. The link we shared for the iPhone User Guide, what happens when you scroll to the bottom and try to download the guide? You can also open the Books app on your iPhone and get the guide free in the store. See Find and buy books and audiobooks in Apple Books on iPhone.
When using Face ID for purchases, tapping twice on the right is correct. Are you tapping twice in a row, without a pause between taps? After you are tapping twice, at the bottom of the screen do you see any messages changing? Such as, approving, a circle with a check mark?
Do you have a VPN set up on your iPhone? If so, disable the VPN and try downloading the apps again.
Check the date/time and region to make sure they are correct. Settings > General > Date & Time. If this is not correct it can interfere with the App Store allowing you to download apps.
We’ll be here if you still need help.
Take care!