I started the migration yesterday from my MacBook Air to my new MacBook Air. How can I tell if it’s actually doing anything? The same screen has been there all night.

Because Apple has so frequently changed ports these last few years I strongly recommend using a TimeMachine backup to migrate data. WiFi is too slow. Theoretically using a wired network connection should work but all too frequently TM stalls with a network connection. Knowing which cables will work between MacBook generations can be frustrating - and expensive if you’ll be using that cable just the one time.

However everyone needs a backup drive and restoring/migrating from that backup drive is very reliable.

Mine is doing the same thing, did your files transfer