Licensing is quite simple. You got Advanced and Enterprise. Beyond that licenses are not model specific. 1 AP license covers one AP, simple as that.
As for AP models i usually settle for MR44 for indoors and MR76 for outdoors unless a customer has some specific requirements like Wifi 6E or super high density.
For deployment models i almost always go for the "default" mode of using VLAN taggs pr SSID. Read FlexConnect.
In some cases customers need all wireless traffic to be backhauled to a datacenter. For that you would need an MX located in the DC to act as a droppoint for this traffic.
I recommend that you go through Meraki FIT and CMSS certification track before you start deploying.
https://community.meraki.com/t5/Meraki-Certification/ct-p/cmss
https://community.meraki.com/t5/Meraki-FIT/ct-p/merakifit
Hope this was helpfull.
MLL