how do I restore my Find My app?

you need to be more specific, we don't know what you're talking about.

here is another guess..

Use your iPhone or Apple Watch as a car key - Apple Support

Or if you simply lost track of some apps that are 'hiding' in the App Library and want to 'restore' them back on your Home Screen?

From your Home Screen, swipe left until you get to the App Library.

Swipe downward and you'll get an alphabetical list of your apps.

Locate the app in the list or type the app name into the search field

Once you've located the app, tap/hold until it raises/selects, then drag it and it'll pop out to your Home Screen

Organize the Home Screen and App Library on your iPhone - Apple Support

keychain?

Set up iCloud Keychain - Apple Support

What do you mean by "keys, etc"?

Find My - Official Apple Support

There is only one "Find My" app. If you have it on your phone, then there's nothing else to restore.

Or are you asking how to restore it to other devices? If so, which ones?

Chris0107 wrote:

keychain?

Good guess!

must not be right though ha ha

Graciella24 wrote:

Keys

Please explain what you mean by "keys". An explanation should include more than one word.

Chris0107 wrote:

must not be right though ha ha

But it was a good effort.