You could talk about the things that you find funny in everyday life or human behaviour, what should be off-limits as far as joking goes, tell funny stories about your past or discuss your favourite comedies and comics. Having a sense of humour can also mean being able to laugh at a bad situation

Can you laugh at yourself ?

Why do we laugh when people fall down or hurt themselves?
What are your favourite comedians or comedy TV shows?

Laughter is the best medicine