Wedding dress shopping help!!!

Guys tomorrow is my very first appointment to do wedding dress shopping!!!!!! Honestly I’m kind of scared as fuck!! I am really insecure in my body because it’s plus size and I’m really freaking nervous!!!!

What do I wear?!?!?! Do I wear shape where under my clothes so when I try on dresses it looks nice???

I’m planning on wearing a strapless bra but what else do I need to wear/bring????