Kalau urusan ini cepat beres, kita tidak perlu repot datang lagi besok.

In this sentence, kalau means if:

• Kalau urusan ini cepat beres... = If this matter gets settled quickly...

Yes, it is very similar to jika, which also means if. The difference is mostly tone:

• kalau = more common in everyday speech
• jika = a bit more formal or written

So this sentence sounds natural and conversational with kalau.

Urusan is a common word meaning something like:

• matter
• business
• affair
• issue

So urusan ini means this matter or this business/issue.

Depending on context, it could refer to paperwork, an official task, a problem to resolve, or any practical matter.

Here, cepat means quickly, and beres means finished / settled / taken care of.

So cepat beres means:

• gets resolved quickly
• is finished quickly
• is settled soon

Even though cepat is often introduced as fast, it can also work like quickly in Indonesian without changing form.

So:

• cepat beres = quickly settled
• not literally fast tidy

In this sentence, beres means something like:

• finished
• settled
• taken care of
• resolved

It is a very common everyday word.

Examples:

• Sudah beres. = It’s done / It’s settled.
• Pekerjaannya belum beres. = The work isn’t finished yet.

So urusan ini cepat beres means the matter gets completed or resolved quickly.

Indonesian often does not need an explicit future marker when the meaning is already clear from context.

In this sentence, the future idea is understood because of:

• the conditional structure with kalau
• the word besok = tomorrow

So Kalau urusan ini cepat beres, kita tidak perlu repot datang lagi besok naturally means something about a future possibility, even without akan.

You could add akan in some contexts, but it is not necessary here.

This is an important Indonesian distinction:

• kita = we, including the listener
• kami = we, excluding the listener

So kita tidak perlu repot datang lagi besok means we (you and I / all of us including you) won’t need to bother coming again tomorrow.

If the speaker meant a group that does not include the listener, they would use kami instead.

Tidak perlu means:

• do not need to
• no need to
• it isn’t necessary to

It is followed directly by a verb phrase.

In this sentence:

• tidak perlu repot datang lagi besok = don’t need to go to the trouble of coming again tomorrow

Other examples:

• Kamu tidak perlu khawatir. = You don’t need to worry.
• Saya tidak perlu pergi. = I don’t need to go.

Repot can sometimes be translated as busy, but in this sentence it is closer to:

• troublesome
• inconvenient
• a hassle
• a bother

So tidak perlu repot datang lagi besok means:

• no need to go to the trouble of coming again tomorrow
• we won’t have to bother coming again tomorrow

The idea is not just being busy, but that the action would be inconvenient or troublesome.

Because repot datang lagi besok works as a phrase meaning to go to the trouble of coming again tomorrow.

Structure:

• tidak perlu = no need to
• repot = bother / go to the trouble
• datang lagi besok = come again tomorrow

So repot describes the effort or inconvenience connected with the action datang.

A very natural English translation is:

• we won’t need to bother coming again tomorrow

Here, lagi means again.

So:

• datang lagi besok = come again tomorrow

In other contexts, lagi can have other uses, such as marking an action in progress in informal speech:

• lagi makan = eating / in the middle of eating

But in this sentence, it clearly means again.

It most directly goes with datang:

• datang lagi besok = come again tomorrow

So the meaning is that the extra trip would happen tomorrow.

The whole second clause is:

• kita tidak perlu repot datang lagi besok = we won’t need to bother coming again tomorrow

Indonesian often does not need an explicit word like then in conditional sentences.

English often says:

• If this gets settled quickly, then we won’t need...

In Indonesian, just putting the two clauses together is enough:

• Kalau ..., kita tidak perlu ...

The conditional relationship is already clear from kalau.

Yes. Indonesian allows both orders.

Original:

• Kalau urusan ini cepat beres, kita tidak perlu repot datang lagi besok.

Also possible:

• Kita tidak perlu repot datang lagi besok kalau urusan ini cepat beres.

Both mean essentially the same thing. The original version puts more focus on the condition first: if this matter gets settled quickly...

The comma is natural and helpful, because the sentence begins with a conditional clause:

• Kalau urusan ini cepat beres, ...

In informal writing, people may sometimes omit commas, but with this structure the comma is a good standard choice because it clearly separates:

1. the if-clause
2. the main clause

It is neutral to slightly conversational.

Words like kalau and beres are very common in everyday Indonesian, so the sentence sounds natural in ordinary speech. It is not slang, but it is also not especially formal.

A more formal version might use words like:

• jika instead of kalau
• selesai instead of beres

For example:

• Jika urusan ini cepat selesai, kita tidak perlu repot datang lagi besok.

That said, the original sentence is perfectly normal and polite in many real situations.