When computers sends packets to the server, how the wifi AP manages
It really does not. A WAP is a bridge, like a switch, and it bridges frames. Unlike an ethernet switch, which is a transparent bridge (all interfaces are the same layer-2 protocol), a WAP is a translating bridge that translates Wi-Fi frames to ethernet frames, and vice versa.
In the CAM table of my switch, the port associated is the MAC address
of the wifi AP. How the switch knows that a computer is connected to
The switch MAC address table has all the source MAC addresses of every frame entering the switch, even from the interface connected to the WAP, which also has a MAC address table. The switch then knows that for frames destined to a Wi-Fi host, it should send the frames to the interface where the WAP is connected.
It is really the same as connecting two switches together. Each switch will gather the MAC addresses of the devices on the other switch when frames from those devices enter the switch, and it will associate the MAC addresses with the interface where the frames entered the switch.