Do I need to enter lump sum money received from the Social Security Fairness Act on my 2024 taxes or 2025 as no breakdown for what is for 2024 and 2025?

It depends. You will enter only what is on your SSA-1099 and it's quite likely the Social Security Fairness Act portion will be on your 2025 Form SSA-1099. This will be handled next year and your statement will break it down if applicable.