My mac air can not connect the wifi and opening network setting

Hello thuc32,

Thanks for using Apple Support Communities. We're happy to assist if you've been unable to connect to Wi-Fi from your Mac. We'd like to get a few details to get started.

What exactly happens when you try connecting?

This has some good steps that might help: If your Mac doesn't connect to the Internet over Wi-Fi

Let us know if the issue persists. Take care.