You'll probably want to go to the Security Appliance > Configure> Addressing and VLANs page and run standard NAT mode, track by MAC (both the defaults) and then enable VLANs, click on your existing VLAN (should be 192.168.128.0/24 by default) and change it to 10.0.0.0/24 with an MX IP of 10.0.0.1 and VLAN ID 1 for example. Unless you already have other VLANs configured then set the VLAN ID accordingly. That should also enable DHCP on that VLAN automatically, confirm this on the Security Appliance > Configure> DHCP config page. You should be able to connect to a wired port and get a DHCP address to confirm, then connect the cameras and ping them. No need for per-port VLAN configuration unless you specifically need that, and by default all ports will be enabled, trunked, with native VLAN 1 (default). Finally if you need specific port forwarding rules, that's on the Security Appliance > Configure > Firewall page.
You can always open a Meraki Support case for extra configuration assistance or any speed bumps you hit.
Here are some docs for more info:
https://documentation.meraki.com/MX-Z/Networks_and_Routing/Addressing_and_VLANs
https://documentation.meraki.com/MX-Z/DHCP/DHCP_Services
https://documentation.meraki.com/MX-Z/NAT_and_Port_Forwarding/Port_Forwarding_and_NAT_Rules_on_the_M...
https://documentation.meraki.com/MX-Z/Firewall_and_Traffic_Shaping/Firewall_Settings