Ask questions. Anything that comes to your mind. It can be interesting, it can be stupid, it can be about politics, or it can just be about their favorite bubble tea. Just make sure you’re actually curious. This is where smalltalk, like “the weather is really good today,” fails. Engage in smalltalk so you don’t scare people away, but get out of it ASAP through questions. If you know you’re going to meet people, take a few minutes to answer “What do I want to find out?”, “What am I curious about (vis-a-vis them)?”, “What are some fun topics that we can talk about?”. It’ll give you confidence going into the conversation, and it’ll train your on-the-spot question generating ability—a very useful skill, as anyone who’s done Uni App Interviews know.
Then listen. Really listen to the questions. First, because they’re answering you’re question. You’ve made a pact with them to pay attention. If you don’t, next time they won’t answer with as much care. Second, people drop small interesting bread crumbs into answers all the time that you can pick up and from which a new round of questioning can began. They’ll really enjoy bread-crumb follow up questions because it shows that you’ve really understood their answers. And even selfishly speaking, the bread-crumb topics are generally the most interesting ones.
When you really don’t have any ideas, look backwards. Think about what you’ve talked about before. Rehash old questions, interrupted answers, and even just something that you’ve done together. That’s much better than trying to come up with new things, and “I think you talked about this before… [insert question]” always gives people a warm feeling.