It's definitely important to spend some time on their website and various social media pages to show that you have an interest in being a part of their culture. Mentioning a specific part of their website or a post that you really liked would show you spent time doing this. Along with this, finding connections between them and your background or what you are interested in and have already experienced is also key because then it'll be easier for them to imagine you being a part of their culture. But most importantly, be yourself. I remember my interview being very relaxed and just having to talk about myself and interests.