I think you'd look pretty with your hair down with that dress (or in general. You have pretty hair) or in a low ponytail at the base of your neck with a bit of a side-part rather than pulled straight back. Moderate or conservative shoes, like a beige or brown heel.
8AR, eek! I took my polish off and forgot, since I never wear sandals! I have enough time to do a quick coat, I think. I have a neutral/mauve color that should work.