If I order an Apple Watch with a cellular plan, do I have to pay a monthly fee?

You would have to if you decide to activate the cellular portion. In the US, the rates for activation of cellular for an Apple Watch is $10/month. However, understand that the Apple Watch GPS will do everything the cellular watch will as long as the iPhone is close by. Unless you see yourself wanting to leave the iPhone behind a lot, then save the money on the Watch and the plan from your carrier. If you still want the cellular version, you can wait to activate it, and it will work just like the GPS version, or if you activate it, make sure you purchase the correct version. The Watches are regional and cannot roam. Do not buy a cellular watch in a country you do not intend to use it in.

You do not need to pay a monthly fee to order or purchase the watch. You need to pay the monthly fee to your carrier is you activate the cellular service. But, you don't have to activate it.

Yes