hello! my china post package appaears null, could someone help me?

If your package appears 'null'... To us it means 'not existing', but what China Post means is 'in transit' or 'waiting for a plane'.
Don't worry. When they post items for such a small price it may change carriers, and destinations many times as it won't have priority,, it just goes on the first plane with some space to get it closer to the destination. Sometimes it will be days if you are lucky, sometimes it will be weeks.

Thank you very much!