Not long ago, you might have found yourself all dressed up with nowhere to go. Or, more likely, you weren’t dressed up at all. But that was then, and this is now—and looking ahead to June, the cultural calendar is quickly filling up with openings and exhibitions. In New York, Thomas Heatherwick’s long-awaited Little Island has opened like a not-so-secret garden floating above the Hudson River. Out on Long Island at Pace Gallery’s outpost in East Hampton, there’s the David Hockney show “Ma Normandie,” which presents delightful watercolors and depictions of the artist’s home in France.

In California, Dior delivers