During the preparation for the summer vacation, a girl “noha” was killed in mysterious circumstances and the investigator”soliman” and her friends are trying to discover the identity of the murder

The phrase “During the preparation for the summer vacation” does not tell us much and seems irrelevant to what follows.

Drop the placeholders “noha” and “soliman” as loglines should not contain names.

“killed in mysterious circumstances” -> murdered

“discover the identity of the murder” -> find the murderer

What we learned then: a girl was murdered and an investigator and her friends are trying to find the murderer.

This is a generic plot. What is different in your story from all the other murder mysteries? Be specific.