I just back from China last few days

Do i need new simcard for data over there?
Use data roaming so that you can access fb, whatsapp, google map etc
I buy RM50 for 7 days Digi Roaming, utilised 2gb for whole week

Which is more easier to use and have wide acceptance,alipay,tencent?
I use touch n go for buying things at physical store, they do have both alipay QR and wechatpay QR available, tng has better rate and can withdraw later
You only need either wechatpay or alipay for payment using china apps such as DiDi

If you're using iphone, it won't auto-locate your current location using DiDi

Apps that you might need in china:
DiDi for Transport
Baidu Map for Map (there's another one more widely use by chinaman, forgot the name
Touch n Go for payment at physical store, you can scan them or ask them to scan you.
Alipay or Wechatpay for china apps payment only coz you don't want to waste your alipay, unless you can reload on your own. I ask my suppliers to reload for me and I pay them cash.