Talking to my partner about fantasies/trying new things

Kathryn • ✨22 years old from the UK✨
Hey ladies! 
So me and my partner have been together for a while now and I'm still not sure how I can bring up trying new things and his fantasies, does anybody have any advice? 
He's only ever been in one serious relationship before and him and his ex partner didn't really tried anything crazy so I was wondering if anyone could help me on what I could say to him?? Thanks! ☺️