We do not have cable how can we connect out Samsung TV to AppleTV?

You will have to use an HDMI cable to connect the Apple TV set-top box to the TV (or AV receiver).

You will have to use Wi-Fi or wired ethernet for internet connectivity through your home network.

Set up your Apple TV - Apple Support

You need a cable similar to:

https://www.bestbuy.com/site/rocketfish-8-4k-ultrahd-hdr-in-wall-rated-hdmi-cable-black/3720011.p?skuId=3720011

Do not purchase a cheap cable, all cables are NOT built the same way.