Where do I find my teacher's retirement adjustment for the state of Georgia?

You can do your teacher's retirement adjustment from the "Here's the income that Georgia handles differently" page:

Subtractions of Teacher Retirement System Distributions

Georgia allows a subtraction from your retirement income equal to the contributions made from July 1, 1987 through December 31, 1989 that were not deductible by Georgia.  The purpose of this adjustment to Georgia income is to allow a one-time deduction, as retirement plan distributions are received, of previous nondeductible plan contributions.

The current year subtraction from income cannot exceed the current year taxable retirement distributions received. The total subtractions from income cannot exceed the total retirement contributions that were nondeductible for Georgia, but deductible on your federal return from July 1, 1987 through December 31, 1989.