Isolated Wifi with Multiple SSIDs

Installing and Using OpenWrt Network and Wireless Configuration
1

This is with regards to

Isolated Guest Wifi with Multiple SSIDs

and

(which is linked in the forum topic mentioned.
This guide is several years old though.

I try to setup a similar configuration. One TP-Link Archer C7 v2 to a fibre modem. I would like to have multiple SSIDs and a network separation between them. That guide on Medium seemed like a good option, but after having it set-up, I do not get a IPv4 address lease.

The other thing, that I find odd is that there is no device in their /etc/config/network

config 'interface' 'public'
        option 'proto' 'static'
        option 'ipaddr' '10.0.0.1'
        option 'netmask' '255.255.255.0'

Has something changed since that guide was written? Any other considerations?

2

I am relatively new to OpenWRT and have the e8450. I installed OpenWRT 23.05.
I am trying to get up each radio ( 2.4Ghz and 5 Ghz) with Multiple Guest SSIDs.
Each will be on a separate sublet and Isolated. Router is in "Router" mode.

I'm using Luci to do it for now but Im comfortable with the CLI as well.
I need a little help, I want to know the step by step sequencing of how this is to be done. I have seached the forums and knowledge base but I cant see any clear and well defined standard sequence.

Is it: First to add wireless network>then add/configure interface> then add and configure firewall rules>then add and configure traffic rules
If thats correct then do I need to have one of the SSIDS linked to the lan interface and all the guest ssids not linked to the lan interface ?
Is it to be one unique interface linked to one wireless network (so if i need 3 guest ssids (and subnets etc) then do i have separate interfaces for each of the 3 or are all 3 linked to one "guest" interface and one set of firewall rules etc ?

If anyone can help I would really appreciate it.