The best time to plant a tree was 20 years ago. The second best time is now.
-- Chinese proverb

Right now, we're experiencing an ongoing global pandemic, the economy is struggling, and the U.S. presidential election could yield contested results. If that all sounds like a terrible time to start investing, you'd be wrong! Now is always a great time to start investing. 

Like the Chinese proverb suggests, big things need time to grow; the sooner you get seeds in the ground, the better. With plants, sometimes it's best to wait for optimal growing seasons since the annual cycle is predictable. But the market isn't that way; we never truly know what's going to happen next. Looking back through history, however, shows that stocks go up more often than they go down. Therefore, you can play the odds by regularly investing regardless of the season.

Furthermore, the likelihood stocks will appreciate in value increases the longer they're held. Since there's a crucial time element involved, it's important to get over short-term worries and start long-term investing as soon as possible.

Here are four stock investing ideas to get you going.

A row of sequentially taller young plants are hand watered.

Image source: Getty Images.

1. Starbucks and 2. United Rentals: Two long-term winners

Winning stocks create shareholder value. This happens when companies do things like grow revenue and invest profits in meaningful future income streams. Certain companies know how to create shareholder value better than others, and it's why you should look among past winners for tomorrow's success stories.

For two examples, consider Starbucks (NASDAQ:SBUX) and United Rentals (NYSE:URI). Not many stocks have gone up as much as they have over the past decade.

SBUX Chart

SBUX data by YCharts.

Starbucks needs no introduction, but perhaps a refresher on this restaurant chain's opportunities is in order. After a short slowdown to manage issues related to the coronavirus pandemic, the company has returned to opening new locations in China, a country where it could still open hundreds (if not thousands) of new stores.

In both the U.S. and China, it's also prioritizing smaller-format locations to meet the growing demand for delivery options, providing operating leverage by reducing real estate and labor expenses. And its rewards program continues to make improvements enabling it to be a powerful transaction driver.

This isn't a stock that will necessarily crush the market every year. But I do expect Starbucks to be a long-term winner. To go along with this winning performance, you get a nice quarterly dividend, which I believe is one of the best around.

Turning to United Rentals, its stock plummeted over 50% earlier this year because investors feared the pandemic would hurt its business. The company cut costs in anticipation of a big slowdown, but it never fully materialized. Total revenue was only down 15% year over year in the second quarter of 2020, and it's already improving. The better-than-feared quarter resulted in massive free cash flow of $817 million. 

United Rentals' improving results gave management enough confidence to update 2020 guidance, calling for $2 billion to $2.2 billion in full-year free cash flow. That means the stock trades at just seven times this year's estimated free cash flow, making it a true value stock in this market.

United Rentals became a big winner by using strong free cash flow, like in Q2, to acquire other companies in the highly fragmented equipment rental space. It's already the biggest player, but it can get much larger from here. The company estimates it has just 13% market share in North America, with 77% of the market controlled by small operations. In short, this is a company with a long runway. 

Both Starbucks and United Rentals have taken previous opportunities and created shareholder value. I expect they can do it again with their outstanding opportunities, and that's why they're worth considering for your starter portfolio.

A person researches stocks by looking at data on the computer and making notes on a notepad.

Image source: Getty Images.

3. Roku and 4. Pinterest: Two hot up-and-coming powerhouses

They don't have the long track records of Starbucks and United Rentals, but Roku (NASDAQ:ROKU) and Pinterest (NYSE:PINS) are two more stocks to consider for your beginner's portfolio. These businesses are easy to understand, and the companies are building something big.

The website Digital TV Research estimates U.S. households will have 317 million subscriptions to streaming video on demand (SVOD) services by 2025, up from 203 million today. That's more than two paid subscriptions per household and doesn't count free streaming services.

Whether it's through its external hardware products or from its pre-installed operating software, Roku will be powering much of this streaming-video revolution. The company makes money by displaying ads on free platforms and by processing payments for pay-subscription services (among other things), meaning it can win in both scenarios. It had 43 million active accounts as of the second quarter of 2020, up 41% year over year. But that leaves a lot of room for growth not just in the U.S. but also as it expands internationally.

Lastly, here's why you should consider Pinterest as you begin your investing journey. Global monthly active users for this social media website platform are now over 400 million. They are attracted to the platform because of its visual content and lack of the negativity often found on social media. Since Pinterest really is different from its peers, it's setting itself up to attract and retain even more new users.

While Pinterest's audience is there, monetization is severely lacking. But the company is delving deeper into moneymaking strategies, including e-commerce. Earlier this year, it partnered with Shopify to bring small businesses' product catalogs directly onto its platform. It's a natural step to buy a product on Pinterest after browsing "pins" for inspiration, and it could really improve the company's top line in a hurry. The average revenue per user is just $0.70 right now, leaving a long growth tailwind if you invest today.

Get your cash working for you

One last thought: Remember that you don't need a lot of money to start investing. The important thing is to start setting aside investable cash and get it working for you as soon as you can. In 20 years, sitting under the shade of tall trees, you'll be glad you did.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.