what trains do I take to get to union station from Reston

This is Union Station - Denver not D.C.

Get on at Wiehle-Reston East. Transfer to Red line towards Shady Grove at Metro Center.

You take the Metro Red line towards Shaddy Grove from Union Station and transfer at the Metro Center station to the Silver Line on the lower level of the station. Weile-Reston station is currently the last stop so will look for Silver Line trains labeled, Weile-Reston.

Good answer

Is there a direct train between Union Station and Reston? No, there is no direct train from Union Station station to Reston station. However, there are services departing from UNION STATION station and arriving at WIEHLE-RESTON EAST station via FARRAGUT WEST station. 🚆🚌🚕

This is Union Station, Denver, Colorado