WAN/LAN setup help/advice

[Fuggin]

Hello...I have a 4-port nuc that I want to use as a router using proxmox and opnsense in a VM. I am having a hard time understanding the settings within opnsense regarding WAN/LAN

So here's my setup:

Proxmox:
1. In the proxmox node, I create vmbr0-vmbr3 bridges. Shut off firewall rules for each port.
2. vmbr0 will be my assigned WAN port. I do not assign CIDR/Gateway to the port.
3. vmbr1 is my LAN port. I assign a CIDR/Gateway to the port. 192.168.1.2/24 | 192.168.1.254

opnsense VM settings (within Proxmox):
1. I add network bridges for net0-net3 and assign them vmbr0-vmbr3, respectively.
2. Install opnsense, run root, assign WAN/LAN ports. Run installer.

ATT Modem:
1. ATT Modem in IP Passthrough with DHCP-Fixed. I select the assigned WAN vmbr0 port's MAC address on the nuc.
2. I shut off the DHCP server in the ATT Modem.
3. I shut off all the firewall rules in the ATT modem.

This is where it gets tricky for me:

Opnsense webgui:
1. WAN port does not pull a public IP. Do I have to select IPv4 Config type to DHCP? (when I do, it pulls a local IP, even though I have Block private/bogan networks enabled) Do I have to enter in the MAC address of the vmbr0 port from the opnsense VM settings?
2. LAN port is 192.168.1.2 from the proxmox setup. This is presumably to be access the webgui. I want this port to be the DHCP server. So, if I enable DHCP server, put in my range as 192.168.1.1-192.168.253. It shouldn't affect the webgui access IP of 192.168.1.2? Do I also have to put in the MAC address of the vmbr1 bridge as well?

Thanks in advance.