The Washington DC cherry blossoms usually reach peak bloom the last week of March or the first week of April.
This depends on the weather. Typically a few days for peak bloom, but rain or windy conditions shortens that time.
These photos are 4 days apart of the same walkway near the Tidal Basin.
Expect large crowds, especially at the Tidal Basin Cherry Blossoms. Get there early in the morning, but you won't be alone.
You can drive to the area and then explore most of the area on foot. You can also use Uber, the Metro, and regular buses.
Take a walk around the Tidal Basin for views of the Washington Memorial and Jefferson Memorial framed by cherry blossoms.