How do I decide which brokerage firm to open my very first account with?

For most beginners, the big, established brokers are more alike than different: Fidelity, Charles Schwab, and Vanguard all offer $0 stock and ETF commissions, low-cost index funds, and strong reputations. Prioritize a broker with no account minimums, no maintenance fees, access to cheap index funds, fractional shares so you can start small, and an interface you find easy to use. Check that it offers the account types you'll want, such as a Roth IRA alongside a taxable account. Avoid apps that gamify trading or push you toward frequent buying and selling. SIPC insurance, which covers up to $500,000 if the brokerage fails, applies at all reputable members, so it's not a differentiator. Pick one solid broker and start; you can always transfer later.