You probably already have the standard deduction for your filing status for tax year 2018. Look at your tax return. Click on Forms in the upper right of the desktop program screen. Click on Form 1040 on the left side of the screen. On Line 8 is either your standard deduction or your itemized deduction.
Standard deductions for 2018
If you are Married Filing Separately, you must also tell TurboTax that neither you nor your spouse is itemizing deductions. When Married Filing Separately, if one spouse itemizes the other spouse must itemize. Revisit the Spouse information under You & Your Family in the Personal Info section.