Ah, the Geek Squad. Regardless, this should work, but it will require a driver as per the Quick Install Guide. Most likely, it came on that CD.
At this point, you still have two options, and those would be:
- Apple still sells the USB SuperDrive. You could use this for that CD.
- Apple also sells a USB to Ethernet adapter. Using this, along with an Ethernet cable to connect to your router, you can then access the Internet to download the driver.
What we still don't know is why your Mac's built-in wireless stopped working. For that I suggest that you try resetting your Mac's SMC. This may be the only thing you need to do to get Wi-Fi working again, and hopefully, forget either of those options.
Ref: Reset the SMC of your Mac - Apple Support