Tips

1. An Alipay esim is relatively cheap and works quite well. See some discussion / instructions on how to obtain the esim here.
2. Some Google-based services and your university VPNs might not work out-of-the-box in China. You should prepare for that before entering China.
3. You might have problems using Google Maps in China. Apple Maps (default on iPhone) works well, so do Baidu maps and Bing maps.