So should my death knight be unholy spec or frost, and 2h or duel wield? just trying to get opinions and as much info as i can on it. please explain your answer, thanks.

If you plan on fighting alone, you should go Unholy spec, because when you level it up enough you can summon around 10 undead to assist you for a short time, useful in those situations where you are taking too much damage, or if you plan on fighting with others, go frost, it will help your teammates fight off whatever your attacking.