How do I move my IPhone backup from one machine to another?
Find device backups in ~/Library/Application Support/MobileSync/Backup/

To locate a specific backup:


Go to iTunes > Preferences. 
Click Devices. 
Control-click the backup you want and select Show in Finder.


https://support.apple.com/en-us/HT204215



How to back up your devices using iCloud or iTunes

https://support.apple.com/en-us/HT203977