Hi @jamesa.gm3963 - if you purchased the Moto G7 Play from Republic it should come with a GSM SIM already installed. There could be some coverage difference if you are using CDMA now. It’s my understanding that the Moto G7 Play is available for purchase only in specific coverage areas because it can currently support only RW’s GSM SIM card. Others in the Community can correct me if this information has changed recently.
Here’s a link for activating the phone.
Make sure you follow the “I’m Activating on an Existing Account” steps to transfer your number from the Moto X to the new Moto G7 Play.
You are correct that Motorola Migrate is obsolete. Don’t know how important it is to you to move information from the old phone to the new one. But here’s a great overview on moving content: How to Transfer Contacts, Photos, Text messages and Other Info to Your New Phone
We used the SMS Backup and Restore app to move both text messages and call log from our old Moto G1’s to new Moto G6’s.
Hope this helps! Come back if you have other questions or issues.