The UI does contain many explanations as to the operation and best settings for the Router. Clicking on the info items may explain settings you may want help with the settings. Most of the settings, once you have the initial setup, will work with the Default configuration. Special circumstances may make some changes needed but hopefully, info from your ISP will help..
As mentioned, you can set the 2.5 Gbps port to WAN using the UI but there is a discussion as to whether that port is a 2.5 Gbps WAN port or just a normal 1 Gbps WAN port when set in that configuration. Since I don't have an ISP speed over 1 Gbps second, I can't check, maybe you can..
Beyond that, as far as I know, the 6 Ghz radio cannot be used in a secure network operation. It can be turned on using a Registry modification, but will not work using WPA-3 security settings.. This might change, at any time depending on exactly why it will not function correctly.
Maximus Z790 Hero,
Intel i9-13900k
Intel AX411