Two days before some of the world’s biggest tennis stars begin competing at the U.S. Open, 11-year-old Samantha Schneider of Bellmore practiced her ground strokes Saturday morning, a few hundred feet from the main court.

She and other kids played against professional tennis players and instructors as part of the tournament’s Arthur Ashe Kids’ Day at the Billie Jean King National Tennis Center in Queens.

“It was a challenge to get the experience of playing with them,” said Samantha, who showed her skills to the likes of Alison Riske, ranked 59th in the world. “Now I know what it’s like when I get to the pros.”

Kids’ Day, which honors tennis legend Arthur Ashe, includes tennis instruction, skill development, target practice, a chance to view pros practice and a concert.

Thousands of children and their parents came from across Long Island and elsewhere for the event, including Daniel and Ethan Ciccone of Manhasset.

“Woo-hoo!” Madeleine Ciccone, 38, exclaimed as her son, Daniel, lobbed the ball into the corner of the court.

Daniel, 6, has been playing for more than three years, sometimes with grandmother Isabel Fersh, 66, a lifelong tennis player who lives in Syosset.

“He made some good shots,” Fersh said.

Ciccone said tennis offers life lessons that video games and other screen-focused activities do not.

“In this day and age, kids get a lot of instant gratification,” she said. “This is something that if they keep at it and they like it, they’re rewarded with getting better and better. It teaches dedication, motivation and perseverance.”

Ebonie Council, 36, of Queens said the focus required to play well in tennis may help her children concentrate more in school.

“They have to keep their eyes on the ball and think about hitting it to the other side,” she said after Jaden-Miles, 6, and Zekigh, 9, played together against pro player Tommy Paul.

“I like that I can hit the ball with strength,” Zekigh said.

Council likes that her children are active playing tennis in the fresh air rather than sitting inside all day.

“They get to . . . burn energy,” she said.

At Court 17 in the tennis complex, children and adults alike ran to the railing of the stands to get an autograph from 16th-ranked Nick Kyrgios after he finished practice.

“It was, like, impressive,” Vedant Mital, 10, said after Kyrgios — a rising star from Australia with an outsized personality — signed a ball. “I saw Nick on the TV. I can’t believe I saw him in real life.”