Dok čekamo, stavljamo voće na traku i tražimo još jedan novčić.

Dok means while here.

So Dok čekamo... = While we wait... or While we are waiting...

A useful thing to know is that dok can introduce a time clause:

• Dok jedem, slušam glazbu. = While I eat, I listen to music.
• Dok ona radi, ja odmaram. = While she works, I rest.

In some contexts, dok can also mean until, but in this sentence it clearly means while.

Because Croatian present tense often covers both:

• a simple present meaning, and
• a present continuous meaning.

So:

• čekamo can mean we wait or we are waiting
• stavljamo can mean we put or we are putting
• tražimo can mean we look for or we are looking for

English usually has to choose between we wait and we are waiting, but Croatian often does not need that distinction.

In this sentence, the context makes the ongoing action clear, so in natural English it is often translated with are waiting / are putting / are looking for.

The ending -mo shows 1st person plural, meaning we.

So:

• čekamo = we wait / we are waiting
• stavljamo = we put / we are putting
• tražimo = we look for / we are looking for

Croatian usually does not need the subject pronoun mi because the verb ending already tells you who is doing the action.

You could say:

• Mi čekamo.

But usually just:

• Čekamo.

Both mean We are waiting, but the version without mi is more normal unless you want emphasis.

Because Croatian often drops subject pronouns when they are not needed.

The verb forms already show the subject:

• čekamo = we wait
• stavljamo = we put
• tražimo = we look for

So the sentence does not need mi.

If you added mi, it would usually sound more emphatic:

• Mi čekamo, a oni odlaze. = We are waiting, but they are leaving.

Voće means fruit.

Croatian has no articles, so there is no direct equivalent of English a, an, or the.

That means voće can mean different things depending on context:

• fruit
• the fruit
• some fruit

In this sentence, stavljamo voće na traku most naturally means something like we are putting the fruit onto the conveyor belt or simply we are putting fruit on the belt.

Also, voće is often treated as a collective or mass noun, much like English fruit.

Because na can take different cases depending on the meaning.

Here the meaning is motion toward/onto a surface, so Croatian uses the accusative:

• stavljamo voće na traku = we are putting fruit onto the belt

Compare that with location, which uses the locative:

• Voće je na traci. = The fruit is on the belt.

So:

• na traku = onto the belt, movement
• na traci = on the belt, location

This is a very common pattern in Croatian.

Here traka means a belt or conveyor belt, especially in a supermarket checkout context.

So stavljamo voće na traku means you are putting the fruit on the checkout belt.

The basic noun is:

• traka = strip, tape, belt, track

The exact meaning depends on context. In a shopping sentence like this, conveyor belt is the natural interpretation.

Here još jedan novčić means one more coin or another coin.

• još = more / still / yet, depending on context
• jedan = one
• novčić = coin

So literally it is something like:

• still one coin more but in natural English:
• one more coin
• another coin

Examples:

• Želim još kave. = I want more coffee.
• Još jedan trenutak. = One more moment.
• Imaš li još? = Do you have any more?

Because tražiti takes a direct object, and direct objects are often in the accusative case.

So in principle:

• tražimo novčić = we are looking for a coin

However, novčić is a masculine inanimate noun, and in the singular its accusative is the same as its nominative.

So:

• nominative: novčić
• accusative: novčić

That is why the form does not visibly change.

You can see the case more clearly with other nouns:

• tražimo psa = we are looking for the dog/a dog
  Here pas changes to psa because it is masculine animate.

Yes. Jedan behaves like a number and also like an adjective in many ways, so it must agree with the noun in gender, number, and case.

Here:

• novčić is masculine singular
• it is the direct object, so it is accusative
• for masculine inanimate singular, the accusative form of jedan is jedan

So:

• još jedan novčić

Compare:

• jedna jabuka = one apple
• jedno dijete = one child
• vidim jednu jabuku = I see one apple

They are two different verbs:

• čekati = to wait
• tražiti = to look for / seek / ask for

So:

• Dok čekamo... = While we are waiting...
• ...tražimo još jedan novčić. = ...we are looking for one more coin.

Be careful not to confuse tražiti with search only. It can also mean ask for in some contexts:

• Tražim pomoć. = I am asking for help / looking for help.
• Tražim ključeve. = I am looking for the keys.

Because Dok čekamo is a subordinate clause at the beginning of the sentence.

Croatian normally separates that kind of introductory clause with a comma:

• Dok čekamo, stavljamo voće na traku...

This is similar to English:

• While we wait, we put the fruit on the belt...

So the comma marks the boundary between:

• the dependent clause: Dok čekamo
• the main clause: stavljamo voće na traku i tražimo još jedan novčić

Yes, Croatian word order is more flexible than English word order, although some versions sound more natural than others.

The original sentence is natural:

• Dok čekamo, stavljamo voće na traku i tražimo još jedan novčić.

You could also say:

• Stavljamo voće na traku i tražimo još jedan novčić dok čekamo.

That still makes sense, but it changes the rhythm and emphasis a little.

Croatian often uses word order to highlight information rather than to mark basic grammar, because endings already show a lot of grammatical information.