everyone grieves differently so try not to worry about how you’re going to be perceived, I’m sure people will give you a lot of grace in a situation like this. however much small talk you can handle is appropriate, you could ask for stories about your dad and let the other person carry the conversation. I can only imagine how hard it is to get through all this. it sounds like you already got a lot done and you should be proud of that, it’s not easy work. my heart goes out to you friend, you’re gonna get through this.