Definitely wear gear. Civilians get assigned randomly and get shot by both sides. More often people shoot since it's easier than trying to figure out if you have your arm band and if it's in the right place.
I usually go there in my camo or whatever I'll wear in game, but put on my tactical equipment etc once I am there and checked in. Personal preference really. I'll often bring a spare shirt incase I don't want to drive home all sweaty lol As far as changing clothes, they only place to do that sort of thing fully, besides the shirt, would be the porta potties there. Hope this helps.
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