Sciacca sits on Sicily's south coast road between Agrigento and Castelvetrano. By car it is straightforward, though the coastal roads can be slow in summer. Palermo and Trapani airports are both workable, with Palermo usually offering the broader choice of flights.
Buses connect Sciacca with Agrigento, Palermo, and nearby towns, but check times carefully if you plan to continue to Caltabellotta or smaller inland villages. There is no useful railway station in town, so public transport here means buses.