Brokerage account same as a Roth IRA?

Good evening, so I am a 100% P&T disabled veteran. I make 0 dollars in earned income. I got injured while in the service and can no longer work. I make enough to put a little back into savings and a little back into the stock market. I found out recently that since I make no earned income, that I cannot invest into a Roth IRA. AI shows me that since I am married, that I will be at the 0% capital gain tax bracket until I hit around 120k in capital gains/earned income. Would this mean that a regular brokerage account is the same as Roth IRA until it hits that 120k mark? Since I shouldn't be getting taxed on growth or dividends. Am I reading this right? I appreciate the information.