That depends which airport you use. If you use Reagan National Airport (DCA), you're 24 mi away, but can also hop directly on the Metro (Yellow line), which you can take to Rockville (Red line). Dulles International (IAD) is 27 miles away and not Metro accessible. Baltimore/Washington International (BWI) is 41 miles away and has Metro access, but it complicated for anyone not used to navigating a metro or subway system.
Not really, unless you really want it. Most wedding related events will be happening within 1,000 feet of the venue and hotel. Anything beyond that area can be easily reached by Metro or carpools will be coordinated. Note that parking in DC itself is horrendous. But you do you. Link to wedding related locations: https://drive.google.com/open?id=1l0uSyEQkGv7py7eZqE9vzxa8ZOuYPQm3&usp=sharing
Think cocktail attire and fun! Wear something you can walk, stand, and dance in... No point in heels that are a billion miles high or shoes that pinch your toes.
There are lots of people who are baby-sitters in the theatre community where Hope works. We can help match you up with a sitter so the kids can stay at the hotel.
Yes. And YES. The event begins at 6:00pm with activities and the ceremony itself will be shortly thereafter. You are not going to want to be late. 6:00pm in traffic in DC is not a fun time, so allot yourself proper travel time to get to the venue, park, and get up to the space. Heck, plan to be early at 5:45pm and grab a Starbucks or a moment in the sun and save yourself the stress.