Go to Settings 
> App Store, then do any of the following:
- Automatically download apps purchased on your other Apple devices: Below Automatic Downloads, turn on Apps.
- Automatically update apps: Turn on App Updates.
- Automatically play app preview videos: Turn on Video Autoplay.
- Automatically remove unused apps: Turn on Offload Unused Apps. You can reinstall an app at any time if it’s still available in the App Store.
