How to make Apple TV work

I just bought a new Apple TV 4K with Ethernet. I have this same Apple TV in my living room, but an older model. This new one has been a complete nightmare. The Apple Remote will not learn my sound bar controls. Yes, it is up to date. Yes, I’ve put new batteries in the soundbar remote. Nothing works. I have a universal remote on my Apple TV in my living room, so I bought the same one. It will not pair, the Apple TV learn remote function seems to be the only way to set this up and it won’t work correctly. I press the buttons it tells me to, it sets up the first button, the second button it says this button has already been assigned, but it hasn’t. My Apple TV in my living room setup with a code, the code the remote gives for Apple TV doesn’t work. When I put the code in on my Universal Remote it will blink the Apple TV light, but it won’t do anything else. Please help!