Meeting with large apartment owner looking to sell, what should I do?

[Orion Walker]

I happened to run across a message from someone looking to sell a near 50 unit apartment complex in my town off mls. We spoke briefly on the phone and he said that he would prefer to meet in person, so we scheduled to meet up at a local restaurant tomorrow. I don't know much more than that, but I figured it can't hurt to meet with the guy. If nothing else I'll learn a few things.

So, I'm looking for advice in preparation for meeting tomorrow. What should I be sure to ask? What are some basic aspects of how a deal like this would be put together that I should know? What should I or shouldn't I do to establish credibility on my end? 

This would be a big jump upwards, but I do feel that I have enough knowledge/skills/network to do a deal like this if the seller is willing to work with me.

Any and all advice would be much appreciated. 

Thanks!