You are going on your first cruise and you are worried about wrinkles??
You will be on vacation - enjoy it!
Take the "nice stuff" out of your suitcase as soon as you get in your cabin, and hang it up in the closet (there is plenty of space). The rest of your wardrobe should consist of a swimsuit, cover-up and flip flops, to enjoy your days lounging by the pool!
I wouldn't know about line-ups for irons, I've never used or needed one on a cruise. Just a little tip: neatly ROLL up your outfits when packing, usually saves on most of the wrinkling.