Most aspiring singers dream of getting signed to a big label, rubbing shoulders with their idols and having millions of people see them perform. But when Grace VanderWaal lived out that fantasy as a 12-year-old by winning Season 11 of “America’s Got Talent” in September 2016, the thing she was most excited about was being taken out of school.

“School used to be the enemy for me,” she tells The Post. “I was always dying to get out, but then I did get out, and I started to be home-schooled.”

But VanderWaal — who performs on the “Today” show on Dec. 29 — quickly learned a crucial showbiz lesson: Be careful what you wish for.

“I thought I would sleep in, wake up with the birds chirping, do two hours of school, stay in my jammies and eat waffles,” she says. “But I would have so many arguments with my parents because I had the ability to put off [my work]. After a while, I started falling behind and nearly had to redo seventh grade.”

She’s now happily back at school, close to her hometown of Suffern, NY, while simultaneously promoting her debut album, “Just the Beginning,” which dropped in November.

The release marked the end of a whirlwind 18 months for VanderWaal, who turns 14 in January. It all began when she auditioned on “America’s Got Talent” in June 2016, performing her original song “I Don’t Know My Name.” The clip became a viral sensation — it’s been viewed 76 million times (and counting) on YouTube — and judge Simon Cowell remarked that VanderWaal could be the “next Taylor Swift.”

But the quirky, ukulele-driven folk-pop songs on her first album (all of which she at least co-wrote) indicate that similarities to Swift — both old and new — are less overt than Cowell initially thought.

“I don’t see the correlation except that we both have bangs and we’re both blond and we’re both songwriters,” says VanderWaal, distancing herself from the hype. “I think it was a comment in the spur of the moment.”

Even so, VanderWaal is not short on big-name fans. Her idol, Jason Mraz, banged the drum for her early on, Katy Perry tweeted that she’s “got it” and Stevie Nicks opined that the teenager is “going to the top.”

When she’s not trying to get through the eighth grade, VanderWaal will be back on tour in 2018. (Her mother, Tina, travels with her, while her father, Dave, is a marketing executive with LG electronics.) But with what looks like a one-way ticket to stardom in her back pocket, it’s a surprise to hear that VanderWaal still has other plans for the future.

“I’m thinking about being an art therapist when I grow up,” says the remarkably mature youngster. “Mental health is such an interesting thing, and it’s something I’ve wanted to [explore] for a while. The singing? I’m just going to see where it goes!”