I can't pair my watch to my new phone and I already erased everything on the old phone to be traded in

Hello and welcome to Apple Support Communities, thaisha288,

We understand you're wondering how to get your Apple Watch that was paired to your previous iPhone 12 Pro paired to your iPhone 14 Pro Max. We'd be happy to provide information to help you accomplish this.

You'll have to erase your Apple Watch in order to pair it to your new iPhone:

Unpair and erase your Apple Watch - Apple Support

"How to erase your Apple Watch if you don't have your iPhone

1. On your Apple Watch, tap Settings > General > Reset > Erase All Content and Settings. 
2. Type your password if prompted.
3. For GPS + Cellular models, choose to keep or remove your cellular plan.

• If you want to pair your Apple Watch and iPhone again, keep your plan. 
• If you don't want to pair your Apple Watch and iPhone again, remove your plan. If you aren't going to pair with a different watch or iPhone, you might need to contact your carrier to cancel your cellular subscription. 

1. Tap Erase All to confirm. This resets your Apple Watch to the factory settings.

Now you can set up your Apple Watch again. You'll need the Apple ID and password associated with the watch turn off Activation Lock."

Regards.