Cash Donation - If I use the standard $ 26,000, and can I also use Cash Donation of $6600?

No. The Standard deduction takes the place of all itemized deductions, including charitable contributions.

For 2018, the increased Standard Deduction amounts for all filers are:

• Single or Married filing separately—$12,000.
• Married filing jointly or Qualifying widow(er)—$24,000.
• Head of household—$18,000.

• Single and over age 65 or blind: add $1,600 for age and/or blindness.
• Taxpayer and spouse filing jointly and over age 65 or blind: add $1,300 per person for age and/or blindness.
• Taxpayer and spouse filing separately and over age 65 or blind: add $1,300 per person for age and/or blindness.
• Qualifying widow(er) and over age 65 or blind: add $1,300 for age and/or blindness.
• Head of household and over age 65 or blind: add $1,600 for age and/or blindness.