قبل ما انام، قريت قصة في الكتاب.

قبل ما means before when it introduces a verb clause.

• قبل = before
• ما here helps connect it to the following verb

So قبل ما انام means before I sleep / before going to sleep / before I went to sleep, depending on context.

Because ما here is not a negative marker.

In Egyptian Arabic, after words like قبل and sometimes بعد, ما can act as a linker before a verb. So in قبل ما انام, it does not mean not. It just helps form the expression before [someone] does something.

It can naturally cover both ideas.

Arabic often uses a full verb where English might prefer:

• before I sleep
• before I go to sleep
• before going to sleep

So قبل ما انام is a very normal Arabic way to express that idea.

Because after قبل ما, Egyptian Arabic often uses the bare imperfect verb, without بـ.

• بنام usually means I sleep / I am sleeping / I usually sleep in a main clause
• انام is normal after قبل ما in this kind of time expression

So قبل ما انام is the expected pattern.

Because the verbs already show the subject.

• انام = I sleep
  The ا-/أ- at the beginning marks I in the imperfect.
• قريت = I read
  The -ت at the end marks I in the past.

Arabic often drops subject pronouns when the verb already makes the subject clear.

قريت is past tense: I read.

It comes from the verb قرا (to read) in Egyptian Arabic.
The ending -ت shows first person singular in the past.

So:

• قرا = he read
• قريت = I read

In Cairene Egyptian, ق is often pronounced as a glottal stop rather than a hard q sound.

So قريت is often pronounced roughly like 'areet.

That means an Egyptian speaker may say:

• 'areet rather than qareet

The same thing happens in قبل, which is often pronounced roughly 'abl in Egyptian speech.

Because informal Egyptian writing often leaves the hamza out.

So:

• انام
• أنام

are the same word here.

The version with hamza is more formal/standard in spelling, but the hamza is often omitted in casual writing, texting, and dialect writing.

Because قصة is indefinite: a story.

• قصة = a story
• القصة = the story

So the sentence is talking about a story, not a specific already-known story.

في الكتاب literally means in the book.

It suggests the story is inside the book.
If you wanted to emphasize from the book as a source, من الكتاب could also be possible in some contexts.

So the difference is roughly:

• في الكتاب = in the book
• من الكتاب = from the book

Yes. Arabic word order is flexible here.

You could also say:

قريت قصة في الكتاب قبل ما انام.

That is still natural.
Putting قبل ما انام at the beginning gives the sentence a time-setting first, like English Before I went to sleep, ...

Yes, this looks like Egyptian Arabic.

Clues include:

• قبل ما
• قريت
• informal spelling like انام

A more MSA-style version would be:

قبل أن أنام، قرأت قصةً في الكتاب.

Main differences:

• Egyptian often uses قبل ما
• MSA uses قبل أن
• Egyptian قريت corresponds to MSA قرأت
• MSA normally keeps more formal spelling and grammar endings