I am being asked for net income from a 2024 return, but have not yet filed a 2024 return??? The program will not let me continue until I provide numbers

You can put in an estimate for now and then put the correct number before you file.

Line 23400 less Line 23500 equals Line 23600. So, if your spouse didn't have any social benefit repayments, then Line 23400 is the same as Line 23600.