Hello! My great grandmother recently passed away and I will be receiving a death benefit (nothing huge, I think it is around $2500.00 after her other beneficiaries got their cut) from her teacher retirement. Will this be taxed, and if so what is the going tax rate for something like that?

Some states don't have inheritance tax.

There is no federal tax on inheritances. Some states do tax inheritances. For more information read: Your U.S. Tax Return: Tax on Inheritances

The amount in question is so small that I wold be SHOCKED if any taxes were due.