There's multiple ways to do go about this.
For the corporate users, I'd just have a corp SSID that adds the correct VLAN tag to the incoming packets.
For the guests, either you create a guest VLAN, and go about it that way, similarly to the corp SSID. Or you create a Meraki DHCP SSID that isolates the guests from each other and limits them to access the internet, not the local LAN.
The advantage of the former is that you can define the policies for guests in the same firewall as your other policies. You'll also have more insight into what the clients are doing individually as they're not NATed by the AP.
The advantage of the latter is that your guests are using the same address range over and over in each access point so you don't have to worry about DHCP pools exhausting. Roaming, as a consequence, will be less seamless in this setup.
A bit like described here:
https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Configuring_Simple_Guest_and_Inte...