Hi
It is not possible to delete the Find iPhone app from your iPhone.
To search for the app, when viewing the Home screen on your iPhone:
- Swipe down on the centre of the screen > in the Search box at the top of the screen, type "find iphone" > when the app icon is shown, it will also show (to the right of the app icon) the name of any folder that it has been moved to.
- You can also tap on the icon from within the search results to open the app.
Another option is to reset your app layout. This removes all folders, restores the original wallpaper and returns the Home screen and all apps to their original layout (third-party apps are listed after built-in apps):
Go to Settings > General > Reset, then tap Reset Home Screen Layout.
You may also wish to check that you have set up Find My iPhone:
Go to: Settings > iCloud > Find My iPhone > turn on both options.