You are using a recent OpenWRT build (v21.x & above) Your VLANS for LAN, GUEST & IOT are pre-created and ready to start configuring (see supplied config files) WAN access is available to all VLANs ...
The OpenWrt build-poison scare reveals why router firmware supply-chain security matters for smart home and IoT users.
Developed by Yaxiong Xie under the supervision of Prof. Mo Li (PhD advisor), WANDS group.