Is the line 6b correct 0 for adj gross income 58142 on 6a as I recorded

O is ok.  Actually you will pay less tax if 6b is zero and not taxable.

Social Security is on 1040 line 6a and any taxable amount on 6b.

Up to 85% of Social Security becomes taxable when all your other income plus 1/2 your social security, reaches:

Married Filing Jointly: $32,000

Single or head of household: $25,000

Married Filing Separately: 0

To see the Social Security Benefits Calculation Worksheet  in Turbo Tax Online version you would have to save your return with all the worksheets to your computer.   Or if you are using the Desktop CD/Download Software you can switch to Forms Mode (click Forms in the upper right)

If this is on your federal tax return Form 1040, Line 6a is the total Social Security benefits received in 2024 and Line 6b is the taxable amount of those benefits.  Since Line 6b is 0 none of the SS benefits are taxable.