OP good luck.
I'd ask about medical questions, any issues.
I'd be enthusiastic about what you can offer and the benefits of your local area etc.
Our meeting was a little odd as our birth daughter gave our visitors a puppet show, which helped to break the ice.
I think although it is understandable that you may not feel totally 'sold on' the idea of this or that child, the social workers are making an impossibly difficult situation. They are making a decision about a child's life, I would imagine they will want to find an adopter/couple/family who are excited about this child, aware of any possible issues and up for challenges, ready and willing to ask for and accept help if it is needed.
My goodness it is a challenge, I can see that. I think we were lucky, we were quite sure about our little boy, we just felt very positive about him. We were told not to consider it was a forgone conclusion at matching panel but obviously some one we really wanted.
I think if I were a social worked (I am not) I would want to see a person who had thought about this child and was really interested in that child, not just a baby or any baby etc. So this is hard because there is not a massive amount to say about a small baby. I think I'd want to feel these parents are a safe pair of hands, they are ready. But in a really relaxed and nice way.
Good luck. 