Sorry this may seem like a silly question but I am genuinely having trouble with this when meeting new people.

When meeting people at a party/gathering setting, I am fine with actually approaching. I just have trouble with what to talk about after. I want to be able to make the conversation interesting. I have heard people say 'just talk about anything' but I still get stuck. How can I have a interesting conversation that flows with someone I have just met?

EDIT: thanks for all the replies!