Can I change my state tax from asking for a school district number if I attend university not k-12

No.  The school district number has nothing to do whether the tax filer (you) attends school.  The state wants to know what school district you live in, for various reasons; one of which may be that your school district (SD)has an income tax separate from the state tax. 

Ohio is particularly notorious for their numerous taxing SDs. Some other state have a few. 

If your state tax form is asking for a school district number, it typically refers to the district where you reside, regardless of whether you attend university or K-12. 

Some residents of certain school districts are subject to tax for the district they live in---it is a local tax.