1.What can I do for you?/ Can I help you?/ What's up?
2.Which bussiness do you want to handle?
3.There are too many people here now. Please wait in the rest room over here.
4.There are too many people here who are handling bussiness, / There are too many people here who come to buy the bus/train ticket. When the people get less, I wil tell you. At than time, you can come here.