The agency is offering free rides Saturday from 1-4 p.m. Many events are planned at the line's six new stations.
"Just come out and find out what it's like," DART spokesman Morgan Lyons said.
"We're excited about all of the new connections along the line," Lyons said. "You've got major education centers all along the corridor, but you've got major employment centers."
On Friday an inaugural Green Line train broke the ceremonial ribbon at the Frankford Road Station in Carrollton. The station is at the northern end of the line. Starting in June, Denton County Rail will take passengers further.
North Texas leaders say light rail will spur development around stations as well as reduce congestion and air pollution.
"These are the sorts of things that we need to push our city forward," Dallas Mayor Tom Leppert said. "It's a city where there's great opportunities, and I think we're capitalizing on those."