Grady High School is near the Midtown MARTA station on the red/gold rail line. It is about a 15-20 minute walk — take the 10th Street exit out of the station, turn right and walk about four blocks.
Bus 36 and 109 that depart from the Midtown Station also stop near the school. It is free to ride the bus if you are transferring from a train. For real-time bus arrivals, use the OneBusAway website or app. The MARTA on the Go app has printed schedules, or look up your route online.