@ericliu any update? Also, are you plugging in the AP where it can grab a DHCP address and begin reaching out to the cloud, or will you have to configure a static IP and gateway to prime the AP?
If you're not behind a restrictive firewall or proxy (that blocks outbound connections) and if there's DHCP, Meraki equipment is plug and play. Also note that even if there's a restrictive firewall that even blocks outbound connections by default, the AP will also attempt to make a "backup cloud connection" over ports 80/443.
So if DHCP is in place, check if you have outbound firewall restrictions on the ASA, and/or if you might be behind a restrictive proxy. As others pointed out, you might need to open a couple ports such as UDP/7351 for cloud communications.
If there's no DHCP, you may need to connect to an SSID on the AP (like the meraki setup SSID) and point a browser to ap.meraki.com and use the local status & configuration page to prime the AP with its static IP/GW settings, or possibly with proxy login info. More info on that here https://documentation.meraki.com/zGeneral_Administration/Tools_and_Troubleshooting/Using_the_Cisco_M...