Security First Act This bill reauthorizes the Operation Stonegarden program from FY2024 through FY2027 and addresses other border security issues. (Operation Stonegarden provides grants to enhance the border security capabilities of state, local, and tribal governments.) From FY2024 through FY2027, the money from unreported monetary instruments seized from individuals crossing the U.S.-Mexico border and transferred into the Department of the Treasury general fund shall be made available without further appropriation to the Department of Homeland Security (DHS) to fund Operation Stonegarden. DHS must report to Congress on (1) DHS hiring practices from 2018 to 2021, and (2) whether certain Mexican drug cartels meet the criteria to be designated as foreign terrorist organizations. DHS must also periodically report to Congress about the technology needed to secure the U.S.-Mexico land border.