Chongqing, Chengdu, Jiuzhaigou, Xi'an, Xinjiang which place to go first

I, i am planning to visit these place, but i'm confuse which place to go first, because in the map Jiuzhaigou and Xi'an are the same far from Chengdu.
I ll start my trip from Nanning -> Chongqing -> Chengdu -> Jiuzhaigou -> Chengdu -> Xian - Urumqi, is it ok?
And another question is do i need permit to enter Xinjiang?
Thanks!