VENICE, Italy (AP) — Harry Styles already has an enviable acting resume for a newcomer, from Christopher Nolan's “Dunkirk” to the upcoming “Don’t Worry Darling” and “My Policeman.” But the pop star said Monday at the Venice International Film Festival that, with acting, he often feels as if he has “no idea what I’m doing.” Styles’ arrival on the Lido, where “Don’t Worry Darling” is having its world premiere Monday night, has been one of the most anticipated events of a festival full of stars. At a press conference before the premiere, Styles was peppered with questions about his fans, his career and whether or not he would work with director Olivia Wilde again — neither of which he answered. In “Don’t Worry Darling,” Styles plays Jack, who works for the mysterious Victory Project, run by Chris Pine’s charismatic cult-like leader, in a mid-century-styled experimental community.