What I would try doing, in response to both of your questions, is doing a little bit of investigating about him. Get to know some of his friends, and see what he's like. That should tell you some more things he's interested in, and then you can have some guaranteed topics for the next time the two of you are in a casual, conversational atmosphere.
I will tell you, though, that just because you don't have substantive conversation with him, doesn't mean you won't later. For the first six months that I knew the ENFJ guy who would grow to be my best friend, we only talked about YouTube videos. JUST that topic! ESTJs can be cautious people in terms of making the first move, so if the two of you end up having some chemistry, and if things go smoothly, you'll be friends. But don't look for open displays of friendly affection - an ESTJ's sweet gestures can be hard to appreciate, for some, because they don't realize how much meaning the ESTJs put into the sweet gestures.
Wow, I'm going too far with this topic! Lol. Either way, it's either all that, or he's genuinely not interested in talking to you, in which case you'd have to work a lot harder to get him to be your friend.