NEWBIE ALERT! HELP!!!

[DrJon]

Evening all,
I have JUST set up OPNsense for the very first time. I have never used it before and have no idea what I'm doing. I have installed it on a WatchGuard XTM 5 Series. I want to be able to set it up correctly and with no holes in the security. I am pretty good at following instruction and learning. I do have some networking experience as I have a server with Active Directory and multiple workstations, smart home equipment, media server etc etc
I have played with pfsense in the past, but never live and came across opnsense while playing about and learning. I have opted for opnsense as I hope it will lend itself to my needs and understanding better than pfsense. certainly visually the gui is much better and simpler to use.


Can anyone help with:
getting the initial set up correct so I can introduce the firewall into the live network without the wife shouting at me because nothing works!! 
and I have read that the LCD panel on the front can be made to work.

huge thanks in advance to anyone that can take me under their wing and help out!

[binaryanomaly]

https://www.bod.de/buchshop/practical-opnsense-markus-stubbig-9783748107231