Dupont Circle is well-served by Metro's Red Line to Dupont Circle (two exits: 19th Street – South or Q Street – North).
It is also served by several bus lines, including the D2, D6, G2, N6, L2, 42, and 43. Visit https://wmata.com/ to plan your trip.
And the Circulator departs from 19th Street and N Street NW, on the south side of Dupont Circle to Rosslyn. It is an express bus that runs regularly. Visit http://www.dccirculator.com/explore/where-we-go/dupont-circle-georgetown-rosslyn/
Bikes are everywhere! If you don’t have a bicycle, then you can rent one for the hour through Capital Bike Share. Just look for the red bike stands: https://www.capitalbikeshare.com/
Finally, Dupont Circle is one of the most walkable neighborhoods in the country, earning a 98 on the walkability score. So put on your comfortable shoes and explore!