My boyfriend and I have nothing to talk about?

So he and I have been going out for almost a month. We didn't know each other very well and decided to try it out. We turned out to be polar opposites. We like each other, but still, can't find anything to relate to each other at all. Lately I think he's been getting tired of me, he says he's not but I don't know. Sometimes he can talk and talk for ages, but about things that I've never heard of and I don't really know what to say in response. I sometimes plan our conversations, or write a list of things to ask him, just to keep conversations going. I really really like this guy, and he has said he feels the same way. Can we get over this issue with time and become a stronger couple or is it just destined to fail? I know it's only been a month, but I already feel really close to him, and I'm already scared of losing him. Any tips/advise please?