I am a Volunteer Firefighter in Ohio. Can I claim any expenses? If so, what?

Yes. as a volunteer firefighter, you can deduct any expenses incurred during service, such as buying your own equipment & gear, mileage, etc., as a charitable contribution on Schedule A. 

The IRS standard mileage rate for charitable activities is 14 cents per mile (2017).

Google: "Firefighter Deductions PDF" for a comprehensive worksheet.

Also, ask your volunteer firefighter association about state tax benefits. Some states offer a tax credit to those that become volunteer firefighters.

I understand you can deduct these expenses, but where exactly do you enter them on Sch A.  I have not found a question in TurboTax that asks about expenses required for volunteer work, such as firefighter, police reserve etc.

You can claim these in federal>deductions and income>donations to charity 2023. Things like mileage, parking and tolls, trips, uniforms and out-of-pocket expenses can be claimed as volunteer expenses.