My Wi-Fi is not working.

Might I recommend an SMC and PRAM Reset?

First, do the SMC:

Shutdown your MacBook Air / MacBook Pro.

Connect the power adapter to the Mac.

On the MacBook Air keyboard, hold down the Shift+Control+Option keys and the Power button at the same time.

Here's how to reset your PRAM:

Shut down your machine. Yes, all the way down, not sleep or logging out.

Press the power button and then press command-option-p-r. ...

Hold those keys down until your Mac reboots again and you here the startup chime.

Let go of the keys and let your Mac reboot normally.