Do I need to charge the DSi before I play it for the first time?
The DSi comes half charged, while you can play it as soon as you get it (or transfer info over) it is recommended you let it drain once (not completely) before starting to charge it, remember you won’t get the full battery life until a few charge/discharge cycles. Try to charge it to the max and then drain it before recharging it for the first five or so times.