Apple Watch Series 1

I'm not sure if you would be able to pair it to an iPhone that doesn't have service, since the purpose of the watch is as an extension of the phone. Here are the setup instructions for the Watch, Set up your Apple Watch - Apple Support Most of the settings that you create on the Watch are to mirror the iPhone, so he would still need to be setting things up on the phone, and without service, it could be difficult. If you have any problems with the setup, I suggest you contact Apple Support for clarification, because the Watch needs to stay connected to the phone.

You cannot. The Apple Watch requires an iPhone to be paired to for it to work. It will not work with an iPad.