Welcome to the forum from South Alabama!
Become familiar with your new shotgun, there is a plethora of info on here and YouTube. Search YouTube for "shotgun Training" and "Mossberg 500 Disassembly" Order yourself some Azoom snapcaps, 4 is plenty, it'll help you get comfortable safely loading...
The atrocities seen on a daily by our troops are more disturbing than most people can imagine. When that is your reality day after day, week after week, month after month after month...it messes with your head. Most soldiers are barely old enough to drink...they shouldn't have to deal with death...