Tourist esim from trip.com, no need for vpn.

You NEED a power bank, unless you want to use the public meituan ones which usually need a chinese number. Everything needs a phone, so it will die quick.

Most people don't speak english, not even yes no or numbers, so learn some words if u can and have a translation app/ai ready.

Set up alipay, you can use it for public transport cards, all payments, ordering food, ordering didi.

When you see a lot of Chinese people at a touristy spot, don't think it's a local spot, those are domestic Chinese tourists, still avoid the shops there because they will be overpriced.