Coco Gauff, the 15-year-old tennis sensation, says she wants to “change the world.” First she will look to win a U.S. Open match.

Gauff has one last warmup date Wednesday night in North Carolina before storming into Flushing Meadows for her first appearance in the U.S. Open main draw.

And it’s a goodie. The Wimbledon darling, whose professional tournament opportunities are limited by the WTA’s age-restriction rules, is playing a non-sanctioned exhibition match. Gauff will square off against the Open’s No. 2 seed, the surging Aussie Ashleigh Barty, at the site of the Winston-Salem Open, an ATP event. It’s the first women’s match played at the men’s tournament.

Gauff’s big Open-prep appearance prompted tickets to sell out in two hours once announced last month. More than 3,000 fans will be in the stadium, and grounds passes were sold to watch it on a video screen.

Barty, 23, won the French Open last spring and would have vaulted to No. 1 had she made the finals in Cincinnati last week, but she was upset in the semifinals.

“It’s a good opportunity to play a match in a match environment,” Gauff, Teen Vogue’s August cover girl, said at a Tuesday press conference in Winston-Salem. “I’m limited to how many tournaments I can play. Any chance to play against someone on the tour is great. When my dad told me I was coming here, I thought it would be a perfect thing for me to get preparation for the U.S. Open.”

The Open starts Monday. As first reported by The Post, Gauff, ranked No. 139, received a wild-card entry into the Open’s main draw as USTA officials skirted the WTA’s age-15 eligibility bylaws.

Gauff had already received her maximum limit of three wildcards as stipulated by WTA and USTA rules. The Open interpreted the age rule as Grand Slams being exempt. However, in the age section of the bylaws, it defines a WTA event as any tournament that awards WTA ranking points.

Had the Open followed the bylaws, Gauff would have been forced to play in the Open’s free-to-the-public qualifying tournament this week in Flushing.

Instead, Coco is making money in North Carolina and embracing the newfound attention she garnered after Wimbledon. She marched through the Wimbledon qualifiers and advanced to the Round of 16 while captivating the tennis world.

“It’s kind of overwhelming, but you feel so grateful to the people who support me and believe in me,” Gauff said. “Hopefully I can inspire many more people. The platform I’ve been given is amazing, and I just hope I can do things off the court — not just on the court — to change the world.”

The Delray Beach, Fla., product still is coping with her fame.

“I got to meet a lot of cool people,” said Gauff, who played the junior event at the Open last year. “I never really dreamed about all of this — the cameras and everything. I’m still getting used to it. I couldn’t ask for anything better.”

She owned a high-enough ranking to enter the qualifier of the Citi Open in Washington D.C. last month amd squeezed into the main draw, but lost in the first round to 77th-ranked Zarina Diyas on July 30. That was Gauff’s last competitive match.

The Winston-Salem venue offers Gauff a chance to experience Open-like conditions, including playing at night — which she enjoys. The match will be aired on the Tennis Channel at 7 p.m.

Gauff said the Winston-Salem hardcourt surface and the balls are exactly the same as the Open’s.

“I’m super-excited,” Gauff said. “I don’t get a lot of opportunity to play in these atmospheres and to play against a great player. It’s good preparation for the U.S. Open.

“I’m from Florida, we have a little bit of a breeze. Here, there’s not much of a breeze, same as New York. So it feels good to play in similar conditions, and maybe when I get to New York, I won’t be able to tell a difference.’’

Barty is already impressed after meeting Gauff for the first time Tuesday in what could become a long rivalry. When Barty showed up at 9:15 a.m. for a practice, Gauff had already been out there for one-and-a-half hours. “I sit here and feel old,” the 23-year-old Aussie quipped.

As part of her exhibition agreement, Gauff popped into a tennis clinic for middle-school and high-school kids.

“A little weird,” Gauff said. “They’re the same age as me and a lot of them were nervous. I was trying to get them not to be nervous. I’m a normal 15-year-old off court. It was super fun. I don’t get opportunity to hang out with people my age.”