Welcome to the community!
In addition to the questions FidoRanya noted above...
You mentioned you were overseas. Are you trying to use a phone you bought from abroad? What phone do you have? Have you verified it has compatible bands/frequencies? You can verify whether the bands/frequencies are compatible here.
Hope this helps
Hey @robbie_7 ,
Can you tell us a little more about what issues you're experiencing?
You can't connect to a Network? Or are you connected to a Network and you're not able to make calls?
Also, where are you located right now? The more details the more we can do to help :)!