When I've entered China (not on the family visit visa), the entry form has been simple but you are asked to give the address and phone number where you will be staying. Have that accessible to you as you will complete this form during the flight. You probably also need to answer that you are not bringing guns, illegal drugs, or money in excess of $US10,000; these are typical questions on the landing cards of many countries. You also need to write information on the date, airline, and flight number for when you will leave China, so have this information with you on board, ideally a printout of your ticket receipt and itinerary from email or the ariline's website. The immigration official might ask to see this.

Definitely have a prepaid credit card. Some airlines do not accept cash on board and you need "plastic" if you want to purchase a snack on a domestic connecting flight. You may also need this for on board entertainment (AVOD videos at your seat or headphoness for a movie shown on overhead screens in coach).