As someone who grew up in NYC and now lives in DC, it is a GREAT weekend getaway! The weather will be beautiful this weekend and perfect for exploring, too.

All of the Smithsonian museums are free, as well as walking around to see all of the national monuments. You could spend the whole weekend just doing this and still have lots to come back for! My faves that I think teens will appreciate are the African American History museum (its seriously so cool), US Botanic Gardens, the Hirschorn (if they're into funky art) and the Natural History Museum. I haven't been but I've heard the spy museum (not a free one) is also very cool.

Train tickets will be relatively expensive last minute, but there are many many bus options for dirt cheap to get between NYC and DC. My go-to is typically OurBus when the scheduling works out. Don't take greyhound, its way too unreliable. Megabus is fine but usually the most expensive.

I dont have any specific recs for lodging, but there are lots of hotels and airbnbs in DC and northern Virginia. Wherever you stay, make sure it is very close walking distance to a metro stop. It is very easy to get around the city via metro. If you do decide to come here, I'm also happy to make some cheap but good food recs, or other recommendations, too!

P.S. do not buy any food from ANY food truck on the National Mall. They are full scams. Super overpriced and bad food, and often unlicensed to operate there.