How to use Migration Assistant to transfer data from my old MacBook Pro to my MacBook Air M1?

You have a variety of options. The 2011 MBP has a Thunderbolt port for which you can use a Thunderbolt to USB-C cable. It also has an Ethernet port that you can use to establish a network connection to your router, or an Ethernet to USB-C adapter, which you can also use for the newer Mac to establish a wired network connection.

The fact no connection occurs over Wi-Fi, if that is in fact correct, implies there may be something else preventing communication though. Wi-Fi can be slow or unreliable depending on one's local wireless environment, but communications should at least become established.

Migration Assistant does work best over a direct cable for faster, stable transfer—Wi-Fi can be slow or fail, especially with older Macs. Use a Thunderbolt to USB-C, Ethernet adapter, or Target Disk Mode with Thunderbolt/FireWire (for 2011 models) depending on ports available.

Thunderbolt on the old computer to USB-C on the new one.

(259925)