I think a gold and pearl or just pearl necklace would complement your dress and shoes beautifully. I love gold! It's so warm and beautiful in photos.
I'm not as sure on a belt. Belts are great accessories especially for defining and slimming your waistline...but the top half of your dress already appears to have a lot of beautiful detailing and I'd hate for a belt to take away from that. Maybe a really slim belt...like an inch or inch and a half wide would work well? Just don't buy one from a bridal store unless you're willing to spend $$$. It wouldn't hurt to shop there just to get ideas but I'd go to Etsy or somewhere similar to find a better price once you've found a style you like.
All your dresses are gorgeous ladies ♥♥
I am so excited to wear my dress again!! I can't wait until she comes in and I can start alterations!!