Turn on your iPhone and Apple Watch
Keep both devices close together
Make sure Bluetooth is turned on your iPhone
Open the Apple Watch app on your iPhone
Tap Start Pairing
Hold your iPhone over the animation on the Apple Watch
Wait for the pairing to complete
Choose Set Up for Myself or Set Up for a Family Member
Follow the on-screen instructions
Sign in with your Apple ID if prompted
Create or enter your passcode
Choose your settings and preferences
Wait for syncing to finish