1st date

So I'm going on my first real date! It's super casual and we'll just be walking around a small town and probably getting ice cream. He didn't actually ask me, but we planned to hangout and then it playfully turned into a "date". It's not cold where I live and I need advice on what to wear. He's casual I know that, but I want to look cute, but not show that I'm super trying. I also need some tips on what to talk about and how to treat a casual date. Like what has worked for you? For this who have experience. Thank you so much. I really appreciate those who can help me out.