Why don't you ASK the university whether there are set textbooks? Surely they are the best people to advise on this?

What gives about being hired with zero experience? Well, there's a constant shortage of qualified teachers in China, so they're basically willing to hire anyone that speaks English, is obviously white, and has a pulse.

Your oral English classes - judging by the experiences of others - will basically be a farce. You have been hired for advertising fodder. The uni can now say "We have English classes run by a foreigner teacher," which may give them an edge over competing universities. Your actual classes will likely count for little in terms of grades, and it is likely you will have scores of students using your class as an excuse to have a nap. This is relatively common practice.

Good luck!