How do you delete apps?

See the following from Arrange and hide apps on your Apple TV - Apple Support

On Apple TV (4th generation), you can delete apps. On Apple TV (2nd or 3rd generation), you can hide them. Just highlight the app and hold down the Touch surface or Select until the app starts to jiggle. Then press the Play/Pause button and choose Delete or Hide.

If you want to add an app back to the Home screen:

• On Apple TV (4th generation), open the App Store, go to your previous purchases, and download the app again.
• On Apple TV (2nd or 3rd generation), you can unhide apps from Settings > Main Menu.

You can also hide your purchases in the App Store, so that you don't see apps on the Purchases page.