I had to laugh. It was the second time in a week that my meeting with Val Weisler, founder and CEO of the international nonprofit the Validation Project, had been postponed.

She's a busy woman, after all. When she's not coordinating almost 10,000 people across 100 countries, matching teens with mentors for internships and community service opportunities, 17-year-old Weisler lives an entire second life as a senior at Clarkstown South High School in West Nyack, New York.

You can check out the origin story in this Meredith Vieira clip. Here's the short version: As a shy high school freshman, Weisler was bullied to the point of contemplating suicide before she "woke up" and decided to find a way to break the bullying cycle. "Nobody wakes up in the morning and says, 'I think I'll be really cruel to someone today,'" she told Vieira. "They have something else in their life that makes them feel small."

Translating that very human concept to people at large has been the least of Weisler's worries. The young self-described social entrepreneur is having to navigate some of the more difficult aspects of running a venture, from spreading her message to finding funding to hiring employees. That, and also applying for college.

Her story is instructive--not only as a guide to getting your project off the ground, but also as a window into the minds of Millennial entrepreneurs. Here are four lessons:

1. Social entrepreneurship is real and effective.

Weisler sees little difference between her nonprofit and a traditional profit-driven startup. Instead of money, she's working to "profit in positive energy." She's already learned that having the greatest product in the world means nothing if you can't get it to resonate with your audience.

While it might sound a bit Polly Anna-ish--you can't pay the bills with "positive energy"--her idea of trumpeting a social cause like one might champion a product or service is hardly without precedent. More and more companies are mixing social and traditional entrepreneurship.

Just look at Toms or Warby Parker, which have garnered huge amounts of success donating pairs of shoes and eyeglasses (respectively) to people in need for each pair purchased.

2. Start small to get big.

Today, the Validation Project partners with top-level athletes such as former New York Giants wide receiver David Tyree (famed for "the helmet catch" in Super Bowl XLII), along with professionals at high-profile organizations like Google, PepsiCo, Dell, and the United Nations.

But it wasn't always that way.

"At first, it was, honestly, me Googling companies, finding their phone numbers, and calling them up," says Weisler, who adds that as the organization gained steam, more people became interested in contributing. "Now, it's really this domino effect," she says. "If we need a Major League Baseball player or someone from the NFL, we can scroll down the mentor list."

3. Never be afraid to commit.

Weisler works 80 hours a week, half as a CEO and half as a student, so you could argue that starting the Validation Project in high school wasn't great for her personal life. Would she rather have done it post-college? The answer is a resounding no.

"I probably wouldn't have done it when I had my life together," she says. "No one starts anything because they wake up and think, 'I'll start a nonprofit today. We start things because something clicks."

4. Have a plan, and execute it.

Weisler began the Validation Project without a plan, budget, vision, or mission statement. She doesn't recommend that path, but she does credit the experience with valuable lessons. Now she says she's primed for her next startup experience, whenever that may be.

"I'm sure that today, tomorrow, 10 years down the road, there will be other ideas that spark my mind," she says. "Every day, I get those ideas, and I will never be afraid to put down my phone and start," Weisler says. "That's what entrepreneurship is all about."