Pop star Ariana Grande may have one less problem in her romantic life, at least that’s what she told us in her biggest hit song. But she definitely has one more problem in her professional life.

Her first big-time tour.

Grande’s Honeymoon Tour performance Sunday at the Xcel Energy Center was too busy, dimly lit and just ill conceived. The emphasis should have been on the vocals — Grande’s forte — and not on overcooked attempts at pizazz.

Flying over the stage on a papier-mâché cloud. Leave that to Katy Perry. Arriving onstage atop a glitzy chandelier. Leave that to Cher. All kinds of choreography with backup dancers (such as a Gatsby-inspired flapper dresses-and-tuxedos scenario). Leave that to Madonna.

With two No. 1 albums and five Top 10 singles, Grande, 21, the former Nickelodeon TV star, may have the drawing power to fill an arena. A near full house of perhaps 12,000 turned out Sunday. But she doesn’t have the experience to pull off an arena spectacle.

On the third night of her first arena headline tour, the petite powerhouse was often hard to find onstage. Blame on it unspectacular lighting, too many dancers (as many as 12) and a series of monochromatic costumes (black, white or silver). To make matters more distracting, there were flashpots, fireworks, stage fog and sometimes confetti — from the opening “Bang Bang” to the closing “Problem.”

But what you want from Grande in concert is grand vocalizing, that four-octave range cascading with deep emotion. At times, it was evident, especially when there were no dancers onstage. The star luxuriated atop a white grand piano, her flowing lavender train spilling all over the floor as she delivered the Adele-evoking power ballad “Just a Little Bit of Your Heart.” It was her most focused and heartfelt vocal of the evening.

Grande displayed her prodigious pipes on up-tempo pieces, too, including “Love Me Harder,” which started with her alone atop a pedestal that rose at the back of the stage. For that number, the pixie with the giant ponytail donned her trademark cat ears atop her head. Of course, they were bejeweled to match her shimmering silver sequined outfit.

At souvenir stands, fans could buy plain white cat ears on headbands (for $40) whose lights would change colors programmed to Grande’s set list. For instance, during “Pink Champagne,” all the cat ears in the arena turned pink.

Grande employed other gimmicks including electronic Mi.mu gloves designed by British pop star Imogen Heap. Whenever Grande moved her hands while singing, the gloves manipulated her voice in weird ways. With such a terrific voice in an era of few stand-out female voices, why would Grande want to muck things up with technology?

Maybe she’s out of touch with some things. Like her core audience. I was surrounded by girls, ages 5 to 11, and their moms. They’ve got school on Monday morning. Should they have to sit through two opening acts (Cashmere Cat and Rixton, a boy band without typical boy-band camaraderie) and wait till 9 p.m. to see the headliner? When the concert lasts till 10:30 and you have a 90-minute drive home, what’s up with school?

“We’re not going,” the 11-year-old next to me promised.

That’s one more problem for Grande.