How to set up my Apple TV remote with my Vizio TV

The Apple Remote (Siri Remote) is for controlling the Apple TV box, not your TV. However, you can have the Apple Remote control the volume on a TV or external audio system, and you can possibly use the remote to wake/set to sleep both the Apple TV and the TV through HDMI-CEC.

Pausing live TV, when supported, is a feature of the live TV app, not of the Apple TV box.

Please contact Optimum TV to ask if they support that feature in their app for Apple TV.

Pausing live TV and resuming where you left off requires a recording to store the video temporarily. That would have to happen on their remote servers, not on you streaming device.