How do I find the WPA2 password for a WiFI network I'm trying to connect to my MAC?

Ask the administrator of the network.

Hi,

Usually WPA2 password is printed on bottom case of WIFi access point or router.

The hardware address perhaps, but not the WPA2 password which is specific to the individual router administrator, who for security sake, would not put it on the bottom of the device unless it was behind a locked door.