when I donate thru DAF, will this reduce my AGI if my donation is above standard deductiion

No.  Your AGI is calculated before being reduced by either the Standard or Itemized Deductions.

Q. When I donate to a Donor advised fund (DAF), will this reduce my AGI (line 11 of form 1040) if my donation is above standard deduction?

A. No. 

Q. When I donate to a  DAF, will this reduce my taxable income  (line 15 of form 1040) if my donation is above standard deduction?

A. Yes, but only by the amount that your total itemized deductions  exceed the standard deduction. 

Q.  When I donate to a charity thru my DAF, will this reduce my taxable income  if my donation is above standard deduction.

A. No.  You get an itemized deduction when you put money (or securities) into a DAF.  You do not get another deduction when you direct the DAF to actually send money to a charity.