Getting ready for my Shanghai trip

I'm expected to be in Shanghai for a whole 6 months from August for work and will have many weekends to explore China!

I do have the following goals for 6 months when I'm there personally:

1. Speak Mandarin - I can speak simple sentences and my tones are rotten so want to be able to speak to the team

2. Travel - I'll have many weekends to go round China but am restricted to Fri night - Sun night. I'm sure there are many fantastic places to go to.

3. Living and getting around - being able to learn Mandarin and eventually be able to read enough will help with basic apps for travel and living. As simple as getting a haircut, or washing clothes etc are things I'm not looking forward to at the start but I'm sure within the 6 months, this will come naturally.

Work is sorting out the visa so that's all good. However, I have been to China before and used surfshark for VPN and that was really flaky. Anything I should do to prep? I want to keep my UK number and get a local sim card and phone. What's best to transfer my phone number to? I heard lebara is actually not bad?

Thanks again for all your help!