Keith, you mentioned you have a COX Business account so they would allow you to have a webserver on port 80. Residential accounts like mine are not allowed to use port 80. Normally, your public ip WAN is DHCP and gets all the info from COX. Look at Status | Gateways
You can configure your internal LAN with DHCP from Services | DHCP Server | LAN
your subnet is 192.168.1.0/24 and the range could be 192.168.1.10 to 192.168.1.99