How can i get to the Panda zoo from the Chongqing train station where i will be arriving from Xian?

Will you arrive at CQ Railway Station or North Railway Station?
If you will arrive at CQ Railway Station, you may walk about 400 meters to Lianglukou Metro Station and take metro line 1 to Daping Station, then you may transfer metro line 2 to the Zoo Station directly.
If you will arrive at North Railway Station, you may take metro line 3 at North Railway Station South Square Station to Niujiaotuo Station. Afterwards, you may transfer metro line 2 to your destination.