Canon MF212w printer that is connected through a USB cable says offline

Did that Wavlink docking station come with an external power supply..?

If so, then make sure that the external power supply is connected and working.

If not, then return it and get a hub to dock that has an external power supply.

Do other USB devices work connected thru the Wavlink docking station..?

If so, then there may not be power to support multiple devices and the printer.

If not, then return that docking station and get a different USB hub or dock.

Does the Canon printer work connected directly to the new iMac using a USB-C to USB adapter..?

USB-C to USB Adapter - Apple

If the Canon Printer is recognized on the iMac 's USB bus (Apple > About this Mac > System Report > USB)

Then try resetting the iMac's Printing System and re-adding the Canon Printer.

Reset the printing system on your Mac to solve a problem - Apple Support

The Canon MF212w is listed as a supported AirPrint model in About AirPrint - Apple Support. What happens if you try to connect the printer to the same network (Wi-Fi router) as the Mac, without additional drivers?

AirPrint works with wireless (Wi-Fi) or wired (Ethernet) network connections, so you could choose to wire the printer to one of the LAN ports of the Wi-Fi router if you so wish.

Also, have you checked whether a printer firmware update has been made available by Canon?

That Canon model, Canon MF212w, is AirPrint compatible. You should be able to connect to it wirelessly.

Try the following:

1 - disconnect it from your Mac via cable.

2 - go to the System/Printers & Scanners settings pane and remove the printer.

3 - add the printer back with AirPrint/Bonjour/wireless connection.