The thing I’ve found best to get people talking is asking intentional questions. As in, ask a question that you expect an answer for which might allow you to deepen the conversation on the topic.

For a concrete example, imagine you meet someone taking photos in public and you talk to each other. Asking a question like “so you like photography then?” Is probably gonna get an answer like “yeah sure”, unless the other person is keen to provide you more details. Instead, asking a question like “what is your favourite photo you ever took?” Or “what kind of photos do you enjoy taking most?” Helps the other person give a concrete answer with some prompt for detail. From the answer, you can then pick what is the part you find most interesting or most likely to be able to talk about and ask another question with the same mindset.

Hopefully they’ll also ask you something in return. If they don’t, you can attempt to share something voluntarily that’s on topic, but if they don’t engage at all it may just mean they don’t want to talk to you. In which case, end the interaction on your terms while it’s still positive and count it as a win.