do all stacked cakes and specialty cakes need to be made from a dense cake mix? Im just learning and for my classes Ive been using a cake mix modified into a pound cake, but the cake to me seems dry. Any recommendations on what type of cake receipt to use for stacking cakes. thanks

No, they don't necessarily need to be made from a dense cake--as long as your support structure is a good one. If you want your cakes to be more moist, I would suggest brushing each layer with simple syrup (equal parts sugar and water, or liqueur heated until boiling and clear) I prefer a dense cake, and mine are never dry.