My Apple Watch

See this link about how to move the watch to a newer iPhone. But make sure the iPhone you own has been updated to iOS 16.2 first --> How to pair your Apple Watch with a new iPhone - Apple Support

Return the watch and get your money back. It's Activation Locked and unless whoever you bought the watch from removes the watch from their account, you've bought a totally USELESS Apple Watch. Apple won't unlock it. We can't help you unlock it.

And if you can't reach or don't know who owned the watch before you got it and you can't get your money back, chalk this up to a bad buying decision and recycle the watch responsibly.

Read this about buying used devices --> The All Too Common SAD Reality of Buying … - Apple Community

If it won't pair and it was used, you likely bought an Activation Locked Apple Watch. If you did, you can't pair it at all.

Your evasiveness is not helping here. Your iPhone 13 is capable of running iOS 16.2, what is the current iOS version on your iPhone?

When you try to pair the watch, exactly what happens? Does the watch ask you to enter anything like the Apple ID on the watch? Does the watch say you need to remove the Activation Lock?

If you can't provide more real details, I can't help you. I'm not a mind reader, nor can I see your watch or iPhone.

Did you ever have it paired with an iPhone previously? If yes, and it's asking for an Apple ID, you need to enter the Apple ID you used when you paired the watch previously.

At this point, I'm going to bow out. It's very difficult to help you with so little information. Contact Apple Support for directly help. It might be best if you scheduled an appointment at your Apple Store Genius Bar and let Apple help you in person.

What Apple Watch model?

Is it new or used?

What happens when you try to pair it?

Is your iPhone updated to iOS 16.2?

Please answer the other questions.