Do u have to have iPhone to set up watch or can I use my iPad both have cellular
can I use my iPad to set up watch
Apple Watch SE
No, an Apple Watch requires an iPhone for setup, and basic functions. Please refer to Set up your Apple Watch - Apple Support, which states:
"To set up and use your Apple Watch, you need an iPhone with the latest version of iOS. You also need to make sure that your iPhone has Bluetooth turned on, and that it's connected to Wi-Fi or a cellular network."