Anything in particular about your wedding itself on the big day that makes you nervous? Some people don't like public speaking so speeches are scary. Some people hate the camera so the idea of being in every photo makes them anxious. And some people just hate being in the center of attention (ie my wife lol).
For me, it was the idea of dancing in front of our family and friends. We didn't take dancing lessons (though we would have if it weren't for covid) so I was already in the mindset that we'd be doing the grade 8 slow dance lol. I know we shouldn't care what our guests think and just enjoy the moment but a small part of me did think "what if they get bored?"