After downloading the new upgrade for my ipad and iPhone many of my apps have disappeared from my front page. The clock i also gone. How do i ge them back where they belong.

Use App Library to search the app you are looking for, see this Apple article:

Organize the Home Screen and App Library on your iPhone

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

If you have find the apps, tap & hold on the app, then drag to the Home screen & drop it.

For iPad see also:

Use the App Library and Home Screen to organize your iPad apps

Use the App Library and Home Screen to organize your iPad apps - Apple Support

Find your apps in App Library on iPad

Find your apps in App Library on iPad – Apple Support (UK)

Move apps and create folders on your iPhone, iPad, or iPod touch

Move apps and create folders on your iPhone, iPad, or iPod touch - Apple Support