please help my pacage did not move froom china yet what dose it mean

PVG actully refers to Shanghai Pudong Airport. NULL is a technique problem of the tracking system of China Post. When some terms cannot be correctly translated from English to Chinese, the systems automatically shows NULL, which means that your package was delivered to the airport for customs check, after which it would be sent out of China. By now, I believe your parcel has been very close to your country. Just wait!