When I did GAP and C&O, we spent two full days in DC sightseeing before leaving. We stayed at the HI Hostel in DC. That was in 2013 before covid, I have no clue how hostels are running these days with covid, but I can say that before covid that hostels were a great way to travel for a solo retired person. Cheap, you can be as social or as anti-social as you like, etc. And that trip gave me two full days to spend in Smithsonian.
Bonus since you will be assembling your kit to travel solo - my solo cook kit in the photo. This includes my butane stove, but if I am traveling domestic, I might be more inclined to bring a liquid fuel stove instead.
Starting top row on left, working to right, butane stove, pasta strainer, small measuring cup, small mug (single wall, can also use as a small pot on stove), green plastic bowl nests in pot, plastic bottle in it is for instand coffee and it nests in my coffee mug, lower/middle row on left, small cheese slicer, spatula, another spatula, vintage can opener, spoon and fork, knife with sheath, cork screw (most important), stove windscreen above pot support, the plastic coffee can lid under pot gripper and wood spoon is my cutting board, big titanium pot about 1.2 liters (roughly) above and to right of it is a small fry pan (upside down and in plastic bag to protect non-stick surface) that nests in the pot, and lower right is coffee mug (double wall).
If you buy a liquid fuel stove, you should be aware that travel by airplane is a major hassle.
https://www.msrgear.com/blog/flying-...camping-stove/
Have a great time.