Look out for your mind being completely blown by how awesome this phone is. First thing you should do is shoot a 45 second video outside and replay. See how easy Smart Switch is for all of your data transfer from your old phone. But definitely, definitely get some type of case or cover. I would love to roll with this thing naked... Yes! But in all seriousness even if it's $11, do something to keep the glass from cracking which would totally bum you out. And by cracking it's not like the glass has fallen into pieces, you just don't want any scratches on this thing. You don't want a two-year-old running their hands on your Ferrari.
Read! Read! Read! All the little tips, tweaks, tricks so that you have your phone exactly the way you want it. Worry about the wallpaper and screen lock pictures and ring tones later, understand how to navigate around this phone, take a picture, make a phone call, set up your favorites along the edge, things like that.