Just to clarify the excellent info provided by MrHoffman...
You are correct in that Tracfone isn't supported by the Apple Watch. Here is a list of the supported cellular carriers:
Apple Watch - Carriers - Apple
You can take calls and send/receive messages without a cellular connection, provided your iPhone is within Bluetooth distance of your Apple Watch.
It's up to you whether you want to return the watch for a GPS model, or switch to a carrier that supports it. (Standard return time is 14 days for full refund.)
Hope this helps.