I'n retired and living overseas as an ex-pat, but I maintain a permanent address in California. My sole income is from Social Security, but I rececently inherited money from an estate which I placed in a CD. Will I have to pay taxes on this money, whrn,and to what percentage?:

There is no federal tax on inheritances. Also CA does not tax inheritances. However, the interest income from the CD is your taxable income.
For more information read: Your U.S. Tax Return: Tax on Inheritances