For anyone who finds investment markets daunting, especially younger millennials and Gen Zers, Nasdaq CEO Adena Friedman has a three-word piece of advice: Learn by doing.

It's her most important money advice for all investing newcomers — including her own children, Friedman told CNBC Make It on Tuesday while speaking at the Fortune Global Forum 2024.

"Learn by doing — with small amounts of money, or even on platforms where you don't actually have to use real money," said Friedman. "As you get more engaged and more educated, you can start to take more risks ... and then get more confidence."

Friedman has two sons in their mid-to-late twenties, she said — one of whom took it upon himself to play around with a stock event marketplace app, which lets users track and trade stocks from their phones. He only invests in small increments, roughly $10 at a time, Friedman added.

"He was taking different sides of the trade all night long on, like, what the temperature of New York was going to be overnight," she said. "It was just fascinating ... He didn't even realize he was learning market structure."

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Young people across the country are hesitant with their money right now: 42% of people aged 18 to 34 aren't saving or investing at all, according to a recent CNBC and Generation Lab survey of more than 1,000 Americans. Thirty-two percent of Gen Zers say their fear of losing money holds them back, and 22% say they don't trust the market, found Investopedia's 2022 Financial Literacy Survey.

Experimenting with pocket money is a great place to start, because it helps you learn and get comfortable with the fact that your investment strategies can result in both wins and losses, said Friedman: "You have to be ready for any outcome."

As you get your footing, you can start thinking about long-term investments that'll impact your future, she added.

"That's what's going to make it so that you can afford your schools, or your children's schools, afford a home, and afford to travel the world and experience the world," Friedman said.

The earlier you can start investing, the better, added Barclays CEO C.S. Venkatakrishnan, another panelist at the Global Forum event.

"I think the most important thing for young people to understand [is] that investing in their future is really one of the biggest decisions they can make," said Venkatakrishnan. 'They should start young from that first paycheck, have a really long term view, and the equity markets are a really important part of that."

Other ways to get started include investing in an employer sponsored 401(k) for retirement, which lets you contribute pre-tax dollars, or contributing to a Roth individual retirement account, certified financial planner Douglas Boneparth told Make It in August. Roth IRA contributions are taxed upfront, so withdrawals in retirement are tax-free.

Later in life, you'll thank yourself for starting early, said Friedman: "[Investing] is a foundational element of wealth creation in this country."

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