You may or may not be aware that China blocks several websites making them inaccessible. Some are Google or anything Google such as Google maps and part of Google Translate. FaceBook, Snapchat and others. For this reason we downloaded a VPN to help us bypass China’s Great Firewall. You must do this on your devices BEFORE you get to China.
We used ExpressVPN during our five week stay and it worked like a dream, I would highly recommend it. It is a bit more expensive than others, $12.99 per month) but had good ratings and I can add mine to it. Having access to WiFi is the difficult part but that is a China issue not a VPN issue. When we had good Wifi I typically used the US location, Los Angeles 2 and never had an issue.
I employed Google Translate frequently and you only need Wifi for a few parts of it but the online portions will require the VPN as it’s a Google product.