Anyone know how to pair apple watch to new phone?

Make sure you know your Apple ID password before starting. If the watch has to be erased and re-paired, Activation Lock asks for it, and that's where a lot of people get stuck halfway. Keep the watch on its charger and right next to the phone the whole time too, pairing is slow.

Do you still have the old phone? That changes everything. If yes: update both phones and the watch, make an iCloud backup of the old iPhone, then set up the new one from that backup. Partway through it asks if you want to use your Apple Watch with it, say yes and it moves across with your settings. If the old phone is gone or wiped, you have to reset the watch (Settings > General > Reset > Erase All Content and Settings on the watch itself) and pair it fresh with the new phone. During setup you can pick a watch backup if one exists. Turning on Health in iCloud first is what saves your activity history either way.