May I ask the requirements I need to apply for the visa to spend 10 days with my fiance's family in Shanghai?

Good Afternoon.. My fiance invited me to come with him in Shanghai to spend 10 days with his family before we get marry. This is my first time to apply for a visa and he has already bought our tickets. May I ask the requirements I need to apply for the visa?.. and what is the percentage of the embassy approving my visa?.. I'm a bit afraid they will deny the application because my fiance has already bought the tickets.. Thank you.