Travel
The closest airport is Salisbury-Ocean City Airport.
The major airports nearby are BWI, Philly, and National.
Hotels are tight, given that it is 4th of July weekend. I highly recommend looking at AirBnB and VRBO for rentals, especially for larger groups coming from out of town.
If you would like to stay in Ocean City, it is about an hour and 10 minutes to get to the wedding and reception site.
I have looked into hotels that have availability July 1-4 and listed those below. This is up to date as of June 3.