If you're intimidated by all the choices that come with investing, financial planners suggest trying index funds

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• Investing can be intimidating, but index funds are an accessible way to get started.
• Before getting started, make sure you have an emergency fund in place so you can invest long-term.
• Index funds are generally low-cost, but make sure you understand what fees are involved.

For new and experienced investors alike, it can be stressful to choose which stocks to buy with your hard-earned money. But you don't have to be able to predict which stock will be the next to take off — and you likely can't.

Instead, experts say to consider total stock market index funds, which give you exposure to the stock market more broadly. These funds include companies you know and use every day, like Apple and Starbucks, but they also invest in smaller companies you've likely never heard of from a wide array of sectors (think healthcare, industrials, finance, and technology). These funds track a market index, such as the S&P 500.

"It's a nice, easy way to get exposure to basically everything that's out there in the U.S. market," says Bryan Hasling, financial planner at Modern Financial Planning.

Build an emergency fund first

But index funds are still investments — and investing goes hand in hand with risk.

"There are trade-offs to getting those long-term returns," Hasling says. "This is not something you should do with money you might need anytime soon."

Before you start investing, it's important to have an emergency fund (which financial advisors generally say should be at least enough to cover three to six months of your expenses) as well as money saved for any short-term goals.

If you invest money you may need within the next few years, there's a chance that you'll have to sell when the market is experiencing a short-term correction, Hasling says. "It's only worth it if you have the ability to let the money work over time through different cycles."

You have several choices for brokerage and investment apps

Nowadays, investing in a total market index fund is as easy as buying a stock via an online brokerage account like Charles Schwab or Fidelity Investments, or with an investment app like Robinhood (though you can also buy a fund from the fund company directly if you prefer). You can buy a full share of a fund or a fraction of a share, often for as little as $1.

When you're picking your total market index fund, keep in mind that many of the funds are tracking the same indexes. A lot of the choice will ultimately come down to how much those funds cost. Check a fund's expense ratio, which is the fee associated with the overhead costs of the fund and is represented as a percentage of your investment. Because these funds are passively managed — meaning there isn't a Wall Street professional choosing which securities to buy or sell — the expense ratios are typically below 0.1%.

Index funds diversify your portfolio

Total stock market index funds may make sense to include in any investor's portfolio, but they can especially be good for new investors as they're an easy and inexpensive way to diversify your portfolio.

Susan Dziubinski, an investment specialist at investment research firm Morningstar, identified total market funds as one of the five best ways to invest money.

"Such funds hold appeal for a few reasons," Dziubinski wrote. "For starters, index funds tend to be low cost; they also don't carry any key-person risk because index fund managers aren't actively picking stocks or bonds."

She added that total market funds offer significant diversification by investing very broadly. That diversification is key since it means that if some stocks in the fund tank, others may hold steady or even gain in value. The risk associated with investing in a total market fund is much lower than the risk associated with choosing a few stocks and hoping they soar.

These funds can also "be great choices for investors as stand-alone investments or in combination," Dziubinski wrote. She says that while a young investor may opt to invest in a total U.S. stock market fund or total world stock fund (which includes stocks from around the globe), that investor may want to add a total bond market fund to their portfolio as they get closer to retirement.