I am 76. I don't have school age children. Do I still have to pay school tax?

[Hal_Al]

What state and what School District?
The school district tax (in most states that have one) is an income tax and levied on the same income that you pay state income  tax on. It's unrelated to dependents still in school.
Some SD income tax (SDIT) is an earned income tax, so it would only be paid by people still working (retirement and investment income is not taxed).
Age exemptions are rare (if any even exist)

[MichaelMc]

We at TurboTax do not have the resources to answer local tax questions. Whether there is an exemption to your local school taxes, based on age, would be a question best directed to your local school board.

As a general rule, everyone has to pay school taxes, because the entire community benefits from having a better educated population.