Why is my total income calculated as $23,276, when I think it should be much larger?

Why do you think it should be more?  What income did you enter that is not being counted?   And...what line are you looking at that is showing the $23,276?   Where are you getting that amount?  Is it on the Form 1040 or is it in a "summary" that you are looking at?

Are you seeing the taxable income?  That is after deducting the Standard Deduction or  your itemized deductions whichever is more.

For 2023 the standard deduction amounts are:

Single 13,850 + 1,850 for 65 and over or blind (15,700)

HOH 20,800 + 1,850 for 65 and over or blind (22,650)

Joint 27,700 + 1,500 for each 65 and over or blind (29,200/30,700)

Married filing Separate 13,850 + 1,500 for 65 and over or blind (15,350)