Wieczorem przygotowuję kolację w kuchni.

• Wieczorem = in the evening
• przygotowuję = I prepare / I am preparing
• kolację = dinner / supper (as the direct object)
• w kuchni = in the kitchen

So the structure is basically: In the evening, I prepare dinner in the kitchen.

In Polish, the verb ending usually shows who is doing the action, so the subject pronoun is often omitted.

Here, przygotowuję ends in -ę, which tells you it means I prepare / I am preparing.

So:

• przygotowuję = I prepare
• ja przygotowuję = I prepare, but with extra emphasis on I

You would add ja only if you want contrast or emphasis, for example:

• Ja przygotowuję kolację, a on zmywa.
  I’m preparing dinner, and he’s washing up.

Because kolację is in the accusative case, which is used for the direct object of the verb.

The basic dictionary form is:

• kolacja = dinner / supper

But after a verb like przygotowuję (I prepare), the thing being prepared goes into the accusative:

• przygotowuję kolację = I’m preparing dinner

For this feminine noun:

• kolacja = nominative
• kolację = accusative

This is very common in Polish:

• mam kawę = I have coffee
• czytam książkę = I’m reading a book
• przygotowuję kolację = I’m preparing dinner

Because after w meaning in, Polish uses the locative case for location.

The basic form is:

• kuchnia = kitchen

But after w:

• w kuchni = in the kitchen

So:

• kuchnia = nominative
• w kuchni = locative

Compare:

• Jestem w kuchni. = I’m in the kitchen.
• Stół jest w kuchni. = The table is in the kitchen.

Wieczorem is the normal Polish way to say in the evening.

It comes from wieczór (evening), but in this time expression Polish uses a special adverbial form:

• wieczór = evening
• wieczorem = in the evening

So:

• Wieczorem przygotowuję kolację. = In the evening I prepare dinner.

This is something you largely learn as a set expression. Similar time expressions include:

• rano = in the morning
• nocą = at night
• latem = in summer

It is present tense.

So it can mean:

• I prepare
• I am preparing

Polish present tense often covers both the simple present and the present continuous that English separates.

That means the sentence could mean:

• a general habit: I prepare dinner in the kitchen in the evening
• something happening now, if the context supports it: I’m preparing dinner in the kitchen this evening

Context tells you which is meant.

Przygotowuję is imperfective.

In Polish, verbs usually come in aspect pairs:

• imperfective = focuses on the process, repeated action, or ongoing action
• perfective = focuses on the completed action

Here the imperfective verb is from przygotowywać:

• przygotowuję = I prepare / I am preparing

The perfective partner is przygotować:

• przygotuję = I will prepare / I will have prepared

So:

• Wieczorem przygotowuję kolację w kuchni. = present, ongoing/habitual
• Wieczorem przygotuję kolację w kuchni. = future, completed event: This evening I will prepare dinner in the kitchen

This is a very important Polish distinction.

No. Polish does not have articles like English a/an and the.

So kolację can mean:

• dinner
• a dinner
• the dinner

And w kuchni can mean:

• in a kitchen
• in the kitchen

Usually the context makes it clear. Polish speakers do not need articles the way English speakers do.

No, Polish word order is fairly flexible.

Wieczorem przygotowuję kolację w kuchni is a natural sentence, with Wieczorem at the beginning to set the time frame.

Other orders are possible, for example:

• Przygotowuję kolację w kuchni wieczorem.
• W kuchni przygotowuję kolację wieczorem.
• Kolację przygotowuję wieczorem w kuchni.

These all keep roughly the same core meaning, but the emphasis changes.

In your original sentence, putting Wieczorem first sounds natural because it answers When? right away.

A rough English-friendly approximation is:

VYE-cho-rem pshih-go-to-VOO-ye ko-LA-tsye f KOOH-nyee

A few useful points:

• w is usually like English v, but before the voiceless k in kuchni, it is pronounced more like f
• cz sounds like ch in chop
• rz in przy- sounds like a hard zh/sh sound
• ń in kuchni is a soft ny sound
• final ę is often not pronounced as a strong nasal sound in normal speech

You do not need a perfect accent immediately; the main goal is to recognize the sounds and stress pattern.

Yes, you could, but the nuance is slightly different.

• przygotowuję kolację = I prepare / am preparing dinner
• robię kolację = literally I make dinner, often more everyday and less formal

Both are natural, but przygotowuję sounds a bit more like prepare, while robię is broader and more colloquial.

So:

• Wieczorem przygotowuję kolację w kuchni. = slightly more formal or descriptive
• Wieczorem robię kolację w kuchni. = very natural everyday Polish

Both are correct, but they are not exactly identical in tone.