Fast answer
A strong Polignano evening stays compact: old-town streets, sea-view terraces, the Domenico Modugno seafront, and a dinner plan that remains flexible until current venue details are checked. Add the Pino Pascali Museum when the day needs culture or a non-beach option, and keep sea caves as context unless a boat plan has been checked. The goal is not to chase every view; it is to make the first evening feel like Polignano without depending on unchecked tables, events, weather, or access.
If you only do one thing
Default to a short seafront and old-town loop, then a dinner choice confirmed close to travel. Add the museum before evening when beach weather, heat, or crowding make a slower cultural stop more useful than another viewpoint.