Can’t pair my Apple Watch

Hello. I’m having a problem with my Apple Watch.

I’ve had it paired to my iPhone 7 for some months, then I un-paired it and tried to sell it. I’ve noticed that no one wants it.I tried to pair it again everything was going well until it repeatedly said “Can’t search for updates because you are not connected to the internet. I’ve tried to pair it on like 2 hotspots 2 wi-if’s.

Can someone help me?