July/August US Budget Honeymoon Ideas

Just got married this month, looking into a quick 3-4 day honeymoon ideas. We both don't travel/fly often, and when we do it's with family and friends, so we are a little overwhelmed. Our budget is around $2500 and we'd like to stay in the U.S. We aren't sporty but love food, museums, and relaxing. We've been considering Washington D.C., any Florida beaches, a cruise, or even a theme park if our budget could allow it. If we fly we would be flying out of Nashville, TN. Any suggestions, ideas, or tips are appreciated because we are super excited to travel together alone for the first time but very indecisive.