Hotel
Wedding Block Rates: King Rooms $119 Double Rooms $149 Parking (not attached): Self $25 overnight Valet $25 overnight
Flight
The DC Metro area has multiple airports, but DCA is the closest airport to North Bethesda and is the best option for commuters (i.e Metro, Uber, etc). If you're taking the Metro, I recommend taking the Blue line (Largo) from DCA, then switching to the Red line (Shady Grove) at Metro Center Station, and finally getting off at White Flint Station.
Flight
The DC Metro area has multiple airports, but IAD is the 2nd closest airport to North Bethesda and ideal for car rentals. Also, Dulles has a toll free road to I-270 but you'll have to quickly cross multiple lanes after entering VA-267. It's really easy to miss! Otherwise, you'll need to rent an EZ-Pass or pay cash. BWI is an alternative option if you plan to fly Southwest.
Travel Note
If you plan to use the Metro, you can buy a metro card at any station. Since you have to tap in and tap out you'll need to buy a card for each traveler. Also, metro prices are not a flat rate, they vary based on final destination.