Have the clamps been removed from the bellows inside the clock as described in the instructions?
Has the cuckoo’s door been “unlocked”? You have to turn a little wire to the side, that secured the door while shipping.
Please check the position of the night shut-off. The most common reason why cuckoo and music do not work is that they have been turned off. With some clocks the night shut-off is a switch at the left side of the clock, with other types it is a wire under the clock. Check both positions of the night shut off and make sure that the switch is not “somewhere between” the ON and OFF position.