The currency is the Chinese yuan (CNY / RMB). Bring a little cash for the first day, then exchange at a bank or airport counter if needed.
Day to day, Alipay and WeChat Pay cover almost everything — shops, food delivery, metro QR tickets and campus canteens. Link an international card if your bank allows it, or ask your university how new international students usually top up.
Keep some cash for taxis, small markets or places that still prefer notes. Never send money to strangers who contact you about “visa fees” or “scholarship deposits”.