AHEAD OF TIME: Thaw the grape juice concentrate in the fridge. Chill the Fresca in the fridge. If both are cold you won't need as much (or any) ice which, and that will keep the punch from becoming watered down.
In a large pitcher or punch bowl, combine the thawed white grape juice and Fresca. Stir together.
If desired, add in washed and thinly sliced and halved Cara cara oranges and/or a few washed fresh raspberries.
Punch is best made right before serving so it doesn't go flat. I recommend serving ice on the side or adding as it's served so the punch isn't watered down.