Please see the following on how to connect to the Apple TV - https://support.apple.com/en-us/HT204289
In brief:
Mirror your iPhone, iPad, or iPod touch
Use Screen Mirroring to see the entire screen of your iOS device on your Apple TV or AirPlay 2-compatible smart TV.
- Connect your iOS device to the same Wi-Fi network as your Apple TV or AirPlay 2-compatible smart TV.
- Open Control Center:
- On iPhone X or later or iPad with iOS 12 or later: Swipe down from the upper-right corner of the screen.
- On iPhone 8 or earlier or iOS 11 or earlier: Swipe up from the bottom edge of any screen.
- Tap
Screen Mirroring.
- Select your Apple TV or AirPlay 2-compatible smart TV from the list. Need help?
- If an AirPlay passcode appears on your TV screen, enter the passcode on your iOS device.
Mirror or extend your Mac display
With Apple TV or an AirPlay 2-compatible smart TV, you can mirror the entire display of your Mac to your TV or use your TV as a separate display.
- Connect your Mac to the same Wi-Fi network as your Apple TV or AirPlay 2-compatible smart TV.
- On your Mac, click
in the menu bar at the top of your screen. If you don't see
, go to Apple menu > System Preferences > Displays, then select "Show mirroring options in the menu bar when available."
- Choose your Apple TV or AirPlay 2-compatible smart TV. Need help?
- If an AirPlay passcode appears on your TV screen, enter the passcode on your Mac.