Why no Apple TV sound on my new Samsung tv

Not sure what you intended to do with bluetooth.

The Apple TV app on smart TVs will use the general audio settings for that device. If the TV is set to use internal stereo speakers, then this app will use that as well. If the TV is set to output to an AV receiver, then the Apple TV app will use that as well.

What is your model Apple TV? Identify your Apple TV model - Apple Support

What are your audio settings on Apple TV?

What is your audio setup? How is it connected?