I am 81yrs old and need help on this question and I am a USAA member and need to know if I am eligible for the ELDERLY CREDIT?

Are you asking about the federal Elderly or Disabled Credit?  Very few people qualify for that credit since it has not been increased or updated by Congress in decades.

ELDERLY OR DISABLED CREDIT https://www.irs.gov/help/ita/do-i-qualify-for-the-credit-for-the-elderly-or-disabled

IRS has an online tool to help you determine if you will receive the credit.

Do I Qualify for the Credit for the Elderly or Disabled? | Internal Revenue Service (irs.gov)