Your apartment in China will not be waiting when you arrive. Unlike Korea, schools in China do not provide a fully furnished apartment in advance, but rather pay a generous apartment allowance on top of your agreed on salary. Schools generally will provide up to 2 weeks of hotel accommodations on arrival. This is ample time to find and move into your own apartment. However, you may consider renting a short term apartment through Airbnb, to help you find your footing and save up for the deposit. There are advantages and disadvantages to finding your own place. Many teachers will like having the flexibility to chose where they live and that they can share an apartment with one or more other teachers. Apartments often come furnished, which will relieve some of the start up costs. However, teachers will be required to provide a damage deposit equal to 1 month rent in addition to pre-paying for the first 2 or 3 months. It can be a significant amount of money, so it's important to be prepared for this in advance.
Rent in China can vary significantly, with the highest cost being in Beijing and Shenzhen. However, salaries are generally higher in these cities as well, so it tends to balance out.
There are different ways of finding an apartment.