Apple watch sync with iPhone number

My Apple watch has its own line that is separate from my iPhone. I've paired the two, but the numbers don't appear to be synced. I have been missing phone calls and texts on my watch when my phone is not connected via Bluetooth, and when I try to call out independently using my watch only, the receiver's caller ID shows my watch's phone number. How do I sync the two lines so I can take only my watch with me and not miss any incoming calls/texts from my main phone line? My carrier is Verizon.