On the first afternoon of ComplexCon, a head-spinning shoppable trade show, music festival and general meeting of North America’s sneaker zealots, Martin Pawelec stood out in his tucked-in golf polo.

“I don’t belong here as you can tell,” said Mr. Pawelec, a financial adviser from Chicago. Nonetheless, bloated bags from A Bathing Ape and Anti Social Social Club puddled at his feet. They belonged to his 14-year-old son, who had already jetted off to purchase yet more tees and sweatshirts.

“Not all kids are into sports — some kids are into fashion,” said Mr. Pawelec, who despite sticking out like a fly in someone’s bottle of Prime energy drink, was enjoying himself. “That’s my kid. He likes shoes and clothes and Travis Scott.”

And kids similar to his son? Oh, there’s a lot of them: 60,000 teens, twenty and thirty-somethings (and occasionally some middle-aged, credit-card holding parents) flocked to Las Vegas this past weekend, for ComplexCon. Tickets ranged from $150 to $1,200 for the Cactus Jack V.I.P. tickets that included exclusive merch and a two-night hotel stay.

First held in Long Beach, Calif., in 2016, as an IRL offshoot of the online streetwear authority Complex, ComplexCon has morphed into a youth culture juggernaut. It’s Coachella for kids who can tell you the exact year the first Yeezy Boost came out. It’s ComicCon for people who desire little else than a Chrome Hearts hoodie. It's the Super Bowl of kids describing T-shirts as “hard” or “fye.”

One Complex employee described the event as “streetwear Disneyland.” That isn’t far off. The convention grounds were peppered with town house-size blowup figurines, a cement truck and a carnival hammer game. At one point, members of the Jabbawockeez dance troop were spotted. Later, so was someone in a Sonic the Hedgehog costume.