In my oh-so-humble opinion, Dawn may not be the best choice for your first NCL cruise (although Dawn worked out nicely for Tony Orlando).
I know the Dawn has its fans, but if I were recommending a ship to a first-time NCL-er, I would recommend one of the newer/larger ships. Even if you're not into all the new-fangled bells and whistles (go-karts, ropes courses, etc....which I am definitely not), I think you would get a more accurate picture of what NCL is about. Observation Lounges, District Brewhouse, more specialty restaurants, better shows/entertainment, etc.
I may be wrong (it's been known to happen) and I'm sure people will shoot down my comment (hey, this is CC, after all)...and speaking of CC, one of the favorite phrases around here is YMMV...and yours definitely might.
Of course, if it's an itinerary that you can't find elsewhere, then go for it.