How to delete app?? Help!

On my iPhone, if the app is on a Home screen, I can touch and hold the app, tap Edit Home Screen in the pop up menu, tap the minus sign, then tap Delete App.

Note that some Apple built-in apps cannot be deleted and can only be removed from Home Screen to the app library.

If the app is only in the App Library screen, I can tap and hold the app there and then tap Delete app.

If neither of those options is available, there may be a restriction set on deleting apps. See: https://support.apple.com/en-us/HT201304#prevent-purchases

That sounds like you have a restriction on deleting apps. Did you check that? See below from my previous reply:

If neither of those options is available, there may be a restriction set on deleting apps. See: https://support.apple.com/en-us/HT201304#prevent-purchases