If you don't know us, you probably aren't supposed to be here. Scram!
If you have been given a plus one you can find it in your invitation address. You'll also be able to RSVP for this person.
For women, skip the evening gown and wear a cocktail dress instead. Dressy jumpsuits, rompers and separates are also viable semi-formal wedding attire options. For men, a suit with dress shoes. Other accessories (like cufflinks) are optional. For more information, read this: https://www.theknot.com/content/what-to-wear-semi-formal
There isn't a designated lot, but there is plenty of street parking all around the venue. New Albany is a small town so you shouldn't have issues finding a place to park on the street.