Saya sudah menyiapkan dokumen malam sebelumnya, jadi saya tidak terburu-buru pagi ini.

Sudah marks a completed action (roughly like already). Indonesian doesn’t have mandatory past tense endings, so sudah is a common way to make it clear the preparation happened earlier and is finished.

• With sudah: Saya sudah menyiapkan… = I already prepared / I have prepared.
• Without sudah: Saya menyiapkan… can sound more neutral and may rely more on context to show time.

meN- (here realized as meny-) commonly marks an active transitive verb (a verb that takes an object).

• menyiapkan dokumen = to prepare documents (documents = the object) It’s very common in formal/neutral Indonesian narration.

dokumen can be singular or plural depending on context. Indonesian often leaves number unmarked if it’s not important.

• dokumen = document / documents
• dokumen-dokumen = documents (explicitly plural, often emphasizing “multiple”) You could also specify: dokumen saya (my document[s]) or dokumen-dokumen itu (those documents).

Not exactly:

• malam sebelumnya = the previous night (relative to some reference time; here, relative to pagi ini)
• tadi malam = last night (from the speaker’s perspective “recently, last night”)
• kemarin malam = yesterday night malam sebelumnya can sound a bit more “story-like” or context-linked (previous night compared to the morning being talked about).

Here jadi means so / therefore, linking cause → result:

• Prepared the night before → jadi not rushed this morning. Yes, jadi can also mean become in other sentences:
• Dia jadi dokter. = He became a doctor.

tidak negates verbs and adjectives, and terburu-buru functions like an adjective/state (“in a hurry”).

• tidak terburu-buru = not rushed / not in a hurry
  bukan is mainly for negating nouns/noun phrases:
• Itu bukan masalah. = That’s not a problem.

terburu-buru means rushed / in a hurry. It’s a reduplicated form, and Indonesian typically writes full reduplication with a hyphen:

• buru-buru = hurriedly / in a hurry
• terburu-buru = (being) rushed / hurried
  In informal writing, people sometimes omit the hyphen, but the standard form uses it.

Repeating saya is common for clarity, especially in careful writing:

• Saya sudah menyiapkan…, jadi saya tidak terburu-buru… You can drop it, and it still sounds natural:
• Saya sudah menyiapkan dokumen malam sebelumnya, jadi tidak terburu-buru pagi ini. Including it just makes the subject explicit in both clauses.

It’s not “required” in all cases, but it’s common and helpful when jadi connects two full clauses. The comma signals a clear pause:

• …, jadi … In casual writing, the comma might be omitted, but this version is neat and standard-looking.

Yes. Indonesian time expressions are flexible:

• Pagi ini, saya tidak terburu-buru karena saya sudah menyiapkan dokumen malam sebelumnya. That version puts the focus on “this morning” first, and then gives the reason.