What do I have to prepare for tomorrow's event?
is this sentence correct?
and thank you for your help in advance.

Question

What do I have to prepare for tomorrow's event?
 is this sentence correct?
 and thank you for your help in advance.

Answer

Your sentence is correct.

Answer

It is a correct sentence. Is it what you meant to say? Or, did you mean to say this:

"What do I have to do to prepare for tomorrow's event?"

Answer

Hello Hanan, M'hammed here Labass?
A hundred percent correct