Yikes, that’s the 64 million dollar question. If you have no idea, rent something from rent the runway that suits your shape rather than being a current silhouette.
It seems like you’re pretty casual so maybe keep that in mind. Let the sales girls help you, because they have a pretty good eye, but choose the one you feel most comfortable in. That- I cannot stress enough, your comfort is key. If your uncomfortable, it will read all over you. If you shoes are too high, and boobs are our and you’re not feeling it, it will show. But if you pick something that makes you feel great, that will show too.
Also, make an appt. and go to the store. I should have said that first.
General rules of thumb- Pointy toe shoes over round, blow the budget on the bag, never Chanel -or- Louis Vuitton, its pedestrian, go easy on the make up. Chic ladies were EITHER lip stick OR eye shadow, not both.