Hi, Ann. You can asked the taxi driver inside the city center if he would like to go to the terra cotta and then batgin for the price. It is safe. If you can not get somebody to help you with the telephone number, you can try near your hotel. You can speak Mandrin, so there may not be big problem. As to the Cantonese speaking guide, it is difficult, I think. You can have a guide speaking in Chinese and English there. If you will go with your father, you have to be the interpreter of your father. :-)