I will fly to Shanghai tomorrow, but then I will go to Yiwu. Is it considered local in terms of SIM card, Should I but SIM card in Shanghai or Yiwu?

I will go from Pudong airport to train station and and then to Yiwu, I will spend there 7 days and then I will come back to Shanghai for 4 more days and back home to UK.
I want to be able to use google maps and some language translation apps.
Best Regards.