Why does my heat and ac not work?

Hello, You likely have a bad blower motor (fan motor). When the fan outside turns on, that is to assist in cooling the condenser, but there is a fan located under the dashboard that blows air through the interior. That fan, the resistor that provides power to that fan, or a fuse has likely gone bad, and will require diagnosis. Check the fuse first. You can do that yourself, and maybe avoid a trip to the shop.