Some of these replies are hilarious.
Lace, leather will make you look really try hard unless you wear it in a very relaxed way like a bustier with baggy jeans - and this will only look good on a very slim 22 year old.
As for showing up in a full length gown, it's a date not a wedding anniversary party.
The dresses and jackets being work only is reminiscent of the early noughties when we were all poured into tailored dresses, sky high heels and (probably) control pants.
The bloke who came in talking about a men love a little black dress is actually bang on about men. Men (assuming you're meeting a man) like to see your figure and for you to look feminine. Fussy migraine inducing patterns, huge floaty styles get in the way of that. It's up to you how much you care what they want.
I remember my now (but not then) DP bumping into a woman and having a quick chat. He was relaxed, she wasn't. It was clear something had gone on. It transpired that they had gone on one date but he hadn't followed up. I was surprised. She was really good looking and on a shallow level way out of his league. I asked him why and he shrugged saying no chemistry and she wasn't really making any effort. It was so vague that I pressed him - I was intrigued to what constituted making an effort. He had to think about it then he said "she just didn't seem interested in me or being on the date.. " then almost as an afterthought or he threw in "she walked in wearing jeans".
I don't know why but I found this so bizarre. He had taken her not to be interested because she wore jeans. They probably cost her five times the amount I spend on one of our date dresses and I suspect she looked amazing in them but there you go.
Personally I think the many posts with some form of fitted dresses showing your waist are your best bet but not too far from what you usually wear. A bright colour will be flattering on your skin and make you look youthful. Nice chunky jewellery to show you're taking it as a night out.
I hope you have a great time. Where is the date on and how did it come about?