Kad stignem u hotel, prvo ću raspakirati torbu i staviti stvari u ormar.

This is one of the most important patterns in Croatian.

After kad (“when”), if you are talking about a future event, Croatian normally uses the present tense, not the future tense:

• Kad stignem u hotel... = When I arrive at the hotel...

So even though the meaning is future, the verb after kad appears in the present form.

This is very different from English, but compare:

• English: When I arrive, I will unpack.
• Croatian: Kad stignem, raspakirat ću / ću raspakirati.

So stignem is grammatically present, but in this sentence it refers to a future action.

Because in Croatian, after time words like kad (“when”), future meaning is usually expressed with the present tense, especially with a perfective verb.

So:

• Kad stignem... = correct
• Kad ću stići... = generally not natural here

A native speaker would normally say:

• Kad stignem u hotel, ...

This is similar to another common pattern:

• Ako dođe, reći ću mu. = If he comes, I’ll tell him.

Not:

• Ako će doći... in this kind of sentence.

They are similar, but not always identical.

In this sentence, stignem means something like:

• arrive
• reach
• get there

So Kad stignem u hotel is very natural for When I arrive at the hotel.

Compared with dođem:

• doći = to come
• stići = to arrive / reach / make it somewhere

In many contexts, both can sound close:

• Kad dođem u hotel...
• Kad stignem u hotel...

But stići often emphasizes successful arrival at a destination.

Because Croatian uses different cases depending on whether you are talking about:

• movement toward a place
• location in a place

Here, the verb means arrival/movement toward a destination, so u takes the accusative:

• u hotel = into/to the hotel

If you were talking about being inside the hotel, you would use the locative:

• u hotelu = in the hotel

Compare:

• Stižem u hotel. = I’m arriving at the hotel.
• Ja sam u hotelu. = I am in the hotel.

The same pattern appears later in the sentence:

• staviti stvari u ormar = put the things into the wardrobe
• stvari su u ormaru = the things are in the wardrobe

Because torba is the direct object of raspakirati (“to unpack”), so it is in the accusative singular.

Dictionary form:

• torba = bag

Accusative singular:

• torbu

So:

• raspakirati torbu = to unpack the bag / suitcase

This is a very common feminine noun pattern:

• žena → ženu
• knjiga → knjigu
• torba → torbu

Because stvari is the plural form of stvar (“thing”), and here it is the direct object of staviti (“to put”), so it is in the accusative plural.

For this noun, the nominative plural and accusative plural look the same:

• stvari = things

So:

• staviti stvari u ormar = put the things into the wardrobe

This is why you do not see a different form here, even though it is an object.

For the same reason as u hotel: this sentence describes movement into something, not location inside it.

So:

• u ormar = into the wardrobe/closet
• u ormaru = in the wardrobe/closet

Compare:

• Stavit ću stvari u ormar. = I will put the things into the wardrobe.
• Stvari su u ormaru. = The things are in the wardrobe.

After verbs of putting, going, entering, arriving, etc., Croatian often uses u + accusative.

Yes, both are possible.

The future tense here is made with:

• the auxiliary ću
• the infinitive raspakirati

So:

• ću raspakirati = I will unpack

Croatian also often allows the infinitive to come first:

• raspakirat ću

Both are natural, but there is a style difference:

• ću raspakirati is a very clear standard form
• raspakirat ću is also common and natural

In your sentence:

• prvo ću raspakirati torbu = first I will unpack the bag

The same applies to many verbs:

• Ja ću doći / Doći ću
• Ja ću vidjeti / Vidjet ću

Because after the future auxiliary ću, Croatian uses the infinitive of the main verb.

So:

• ću raspakirati = will unpack
• ću staviti = will put

In your sentence, the second verb staviti is coordinated with the first one:

• prvo ću raspakirati torbu i staviti stvari u ormar

This means:

• I will first unpack the bag and put the things in the wardrobe

The ću does not need to be repeated before staviti, although it could be:

• prvo ću raspakirati torbu i (ću) staviti stvari u ormar

Normally, leaving it out sounds more natural.

Because Croatian usually does not need to state the subject pronoun when it is clear from the verb ending.

Here:

• stignem already tells you the subject is I
• ću raspakirati also clearly means I will unpack

So ja is unnecessary unless you want emphasis or contrast.

Natural:

• Kad stignem u hotel, prvo ću raspakirati torbu...

With emphasis:

• Kad ja stignem u hotel, prvo ću raspakirati torbu...

Croatian is a pro-drop language, so leaving out subject pronouns is normal.

Prvo means first.

In this sentence it marks the order of actions:

• Kad stignem u hotel, prvo ću raspakirati torbu...
• When I arrive at the hotel, first I’ll unpack my bag...

It often appears before the future auxiliary or before the verb phrase:

• prvo ću raspakirati torbu
• najprije ću raspakirati torbu (a close synonym: first / first of all)

Its position is fairly flexible, but the version in your sentence is very natural.

Croatian does not always need to say then explicitly.

The sequence is already clear from:

• prvo = first
• the order of the verbs
• the conjunction i = and

So:

• prvo ću raspakirati torbu i staviti stvari u ormar naturally means
• first I’ll unpack the bag and then put the things in the wardrobe

If you wanted, you could make the sequence more explicit with words like onda (“then”), but it is not necessary here.

Yes, aspect is very important in Croatian.

These verbs are perfective:

• stići = to arrive
• raspakirati = to unpack
• staviti = to put

Perfective verbs present actions as complete, single events. That fits this sentence well because the speaker is talking about a sequence of completed actions:

1. arrive
2. unpack
3. put things away

That is why this sounds natural:

• Kad stignem...
• ću raspakirati
• staviti

If you used imperfective verbs instead, the meaning would change or sound less appropriate here, often suggesting process, repetition, or ongoing action rather than a completed step.

Yes, hotel is a masculine noun.

You can tell from its dictionary form and from the case pattern:

• dictionary form: hotel
• after u with movement: u hotel (accusative singular, same form as nominative for many masculine inanimate nouns)

Similarly:

• ormar is also masculine
• u ormar is accusative singular

So this sentence gives you two common masculine inanimate patterns:

• hotel
• ormar

Yes. Torba is a broad word and can mean:

• bag
• suitcase
• travel bag
• larger carry bag

In this sentence, because you are arriving at a hotel and unpacking, English might translate it as:

• bag
• suitcase

The exact choice depends on context, but the Croatian word itself is normal and natural here.