You could make up some questions first and have them ready before you start chatting. I think it's important to talk about the boring things first just to make people a little more comfortable. What's your name? Where do you live? What do you do (student? worker?) If the person is a student, you can ask... What are you studying? How long have you been studying? How much longer will take to finish? Why did you choose to study that? And be prepared to answer questions like these as well. Don't worry if it sounds a little "planned." That will help you move on to more interesting topics. You can make up a lot about cultural topics too. If you have questions ready, you can quickly pull some out if things become quiet. I think you will see that if you keep conversation moving, it soon becomes a little more natural as you start to learn about each other. I think everyone feels uncomfortable because usually we don't just share all about our lives with perfect strangers. You have to start with more general things and become a little closer as you get to know each other.

My opinion two things. Choose a topic. And honesty in the dialogue.

BRSwratz's answer is very good. I would follow his suggestions/recommendations. Everyone likes to talk about the weather and food. What is the weather like in your country? What is the temperature today? Is it hot in the summer/cold in the winter in your country? What is your favourite food? Do you like cooking food?

It depends which language they speak. Or maybe they can already speak Chinese, you never know!

talk about something interesting