Just arrived - any tips to make my stay easier?

If you haven't already, set up WeChat on your phone.  If you can't register a bank card, ask someone to transfer ( give cash/ they transfer in front of you - little shops are usually obliging). This will make life that little bit easier to pay for this/ that.

I may be wrong here , but the State Council, have an APP that you download to WeChat. I have to enter temperature every morning and evening, after a certain number of days it gives you a digital green quarantine type pass. To get past even my front gate, I have to show this. It sounds like you want to pass cities & airports, I have a horrible feeling you might need this.

I'm sorry to be vague, but better you find out now than later, just in case.

Since you have your phone and a VPN, make sure to work out twice per day (there are amazing 20-30 minute programs , low impact for limited space and no equipement)  because your body will start hurting at some point. Find a couple of interesting books, find people willing to talk with you on the phone... Just make sure you are active and occupied. Read materials for your work... but never forget to move around a lot. Since nothing will be making you tired , sleep is going to be difficult... Work out takes care of it. Apart of that... enjoy it I guess... You can have long baths with relaxing music and stuff, if you're into them...

As long as you are in quarantine.... Since you have your phone and a VPN, make sure to work out twice per day (there are amazing 20-30 minute programs , low impact for limited space and no equipement)  because your body will start hurting at some point. Find a couple of interesting books, find people willing to talk with you on the phone... Just make sure you are active and occupied. Read materials for your work... but never forget to move around a lot. Since nothing will be making you tired , sleep is going to be difficult... Work out takes care of it. Apart of that... enjoy it I guess... You can have long baths with relaxing music and stuff, if you're into them...
After that... I have no idea love

Thank you both for the kind and constructive advice. I have wechat on my uk phone already as I have been using it while waiting for my flight/PU/visa etc - a few months in fact.
If anyone wants info regarding Nucleic acid tests and the visa process I am happy to detail my successful experience -  I was the only westerner on the flight and in the shanghai airport, my company think I may be one of the first allowed in.