Hi Annabella
The temperature in China changes quite a bit in March. In Beijing, for example, it can still be below freezing at the start of the month but rise to up to 15 degrees Celsius by the end of the month. Depending on when you plan to travel, I would pack plenty of cold weather clothing.
As for currency, quite a few Community users have said they got a better exchange rate by waiting until they got to China. But if you would prefer to get some Chinese yuan in advance so you don't have to think about it, I'm sure it won't make much difference. You won't need a lot of cash as all the excursions and meals are included.
Kind regards,
Olly, your editor