TurboTax automatically gives you the standard deduction -- you do not "claim" it. You will see it on line 8 of your Form 1040.
Your standard deduction lowers your taxable income. It is not a refund
2018 Standard Deductions:
Single $12,000 (+ $1600 65 or older)
Married Filing Separately $12,000 (+ $1300 65 or older)
Married Filing Jointly $24,000 (+ $1300 each spouse 65 or older)
Head of Household $18,000 (+ $1600 65 or older)