For the Guest network, users will not be deleted but will be deactivated.
For the corporate network there are several possibilities, the most common is 802.1x, but in those cases you need a Radius server and the same goes for 802.1x with a certificate, you will still need a Radius server.
Another possibility is 802.1x but using Meraki's own base, of course you will have to register users in the dashboard.
You can easily find more explanations on the Meraki documentation.
https://documentation.meraki.com/MR/Access_Control
I am not a Cisco Meraki employee. My suggestions are based on documentation of Meraki best practices and day-to-day experience.
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