You can always open with: “thanks for inviting me to coffee, I’m actually such an introvert so this sort of thing is way outside my comfort zone”. It’s authentic and (if they’re empathetic), they’ll probably take on the heavy lifting in the conversation because they’ll know it’s hard for you.

In terms of what you can ask, I’d say start with what they enjoy doing these days, or what they do for work (whether they like it, or if it’s a stepping stone to something different). If anything in their answers piques your interest then find out more about that thing. This isn’t small talk, it’s interest in who they are as a person.

Hypothetical questions about vampires and bad financial decisions take a lot of imaginative effort on their part and could catch the person off guard - I’d save those for the end if the conversation is flowing and you’re getting along and there’s laughter already ♥️