If you want to learn more about how to invest in a stock, check out the directory of Investing for Beginners articles I've written, sorted by topic or head over to my blog for more esoteric and advanced topics that aren't particularly appropriate for beginners. Whatever happens, remember that stocks are just one of many types of assets that you can use to build wealth and become financially independent. 

In terms of volume, Interactive Brokers is technically the largest online stock trading platform in the U.S. It also advertises itself as the “lowest cost broker,” and for good reason: It only charges a startlingly low $0.005 per trade on stocks, ETFs, options, bonds, mutual funds, and futures (plus a 7 cent per contract fee for options). Technically, that’s still higher than Robinhood, but Robinhood only offers stocks, ETFs, and options (and as we noted above, Robinhood does skim some money off the top of trades via “payment for order flow”).
“I know stocks can be a great investment, but I’d like someone to manage the process for me.” You may be a good candidate for a robo-advisor, a service that offers low-cost investment management. Virtually all of the major brokerage firms offer these services, which invest your money for you based on your specific goals. See our top picks for robo-advisors.