n00b cheating question

I have just come back to the game after playing an incredibly inferior game called Freelancer. It’s just that I can’t seem to get a grasp of this game quite yet.
So, I finally got the cheats to work – sorta.
After I changed all the .ini files and restored the defaults I finally got the ‘destroy target’ cheat to work. However I really stink at combat. Would someone tell me how I would know if the invulnerability cheat is working? Is anything displayed? Is my hull strength still supposed to plummet when I am hit and supposed to be invulnerable?