Walk by the Washington Monument and Tidal Basin to see the Cherry Blossoms. The Cherry Blossom Parade will take place Saturday, April 13 from 10am-12pm. Location: Constitution Avenue NW, between 7th and 17th Streets, Washington, DC
Head to M Street for some great shopping & restaurants. Tony & Joe's or Nick's Riverside Grill on the waterfront are also great spots for happy hour.
There are a ton of great museums you can check out in DC. See the link below for the full list. https://museumhack.com/museums-in-washington-dc/