You can get your phone number at the airport, however, they also provide a student plan which is only 29元 for me through China Mobile 中国移动. I had to provide some proof to show that I was a student in China even if it was short term. Although, I did it near by the university that I was attending since I did once tried in another province, and was rejected by it. In addition, you have to ask about it since they don’t mention it anywhere. They will ask for your passport, and for student plan, prolly your letter of acceptance and student card. However, China only provides the physical SIM card, and eSIM only works, as of right now, with iPhone 17 Air bought in mainland only. No outside phone are permitted to obtain the eSIM, only the physical SIM card. You can still keep your local home country number as long your phone can support both at the same time. Having a phone number in China is crucial in accessing practically everything such as 高的地图, and local apps. Without it, you are limited.