if yes, what episode does he visit lavender town?
Ash visits Lavender Town in Episode #23 The Tower of Terror of the Original Series. Ash, after being defeated easily by the Saffron City gym leader Sabrina, goes to catch a ghost Pokemon in the Pokemon Tower, where he and the gang must deal with the antics of a Gastly, Gengar and Haunter. This is the only episode where Lavender Town is featured. However, the 153rd episode of the Advanced Generation series *"Battle Dome, Fusion of Fire and Water" is set in the Battle Dome part of the Kanto Battler Frontier, and is stated to be near Lavender Town