You should know that Public Mobile is only available to use in Canada and the US. However, you can pick up an eSIM if your phone handles it or a SIM card though this link to use in Jamaica. Then download an app like TextNow and pick a local number to where you live this way you can call back to home for free using the eSIM and people from home can call you on that number too for free.
Nothing, because it won't work at all. You'll need to rely on WiFi, or look into a travel e-sim from carriers such as Airalo or Ubigi. Public Mobile only offers roaming service in the United States.
