Želim da upoznam prodavca.

Because Serbian often omits subject pronouns when they are already clear from the verb form.

Here, želim means I want, so the I is already built into the ending -im.
If you wanted extra emphasis, you could say:

• Ja želim da upoznam prodavca.

But the plain sentence without ja is completely normal and natural.

Želim is the 1st person singular present tense of želeti or želiti (to want).

So:

• želim = I want
• želiš = you want
• želi = he/she wants

In this sentence, želim is the main verb.

In Serbian, after verbs like want, can, must, need, and many others, it is very common to use:

• da + present tense verb

So:

• Želim da upoznam...

literally looks something like I want that I meet..., but in natural English it means:

• I want to meet...

So da is not being translated word-for-word here; it is part of a very common Serbian structure.

Because after da, Serbian uses a conjugated verb, not the bare dictionary form.

The dictionary form is:

• upoznati = to meet / to get to know

But after da, you need the present-tense form that matches the subject:

• da upoznam = that I meet / to meet

So:

• želim da upoznam = I want to meet

This is one of the biggest differences from English, where you would normally use an infinitive: to meet.

Usually upoznati means to meet someone for the first time or to become acquainted with someone.

So it is often closer to:

• meet
• get to know
• be introduced to

It is not usually just a random physical encounter.
For example, upoznati prodavca suggests actually becoming acquainted with the seller, not just seeing him in passing.

Upoznati is a perfective verb. That means it presents the action as a single whole, completed event.

In this sentence, that fits naturally because the speaker wants one completed action:

• to meet / get introduced to the seller

The imperfective counterpart would be upoznavati, which would suggest a more ongoing or repeated process. That would sound less natural here.

So želim da upoznam prodavca is natural because the speaker wants the meeting/introduction to happen as a complete event.

Because Serbian does not have articles like English a and the.

So prodavca can mean:

• a seller
• the seller

The exact meaning depends on the context.

If the meaning shown to you is the seller, that comes from context, not from a separate Serbian word.
If Serbian needs to be more specific, it can use words like:

• taj prodavac = that seller
• ovaj prodavac = this seller

Because prodavca is in the accusative singular, not the nominative.

The dictionary form is:

• prodavac = seller / salesman

But in this sentence, the seller is the direct object of the verb upoznam, so Serbian changes the form:

• prodavac → prodavca

This happens because prodavac is a masculine animate noun.
For masculine animate nouns in Serbian, the accusative singular usually looks like the genitive singular.

Compare:

• Vidim prodavca. = I see the seller.
• Poznajem prodavca. = I know the seller.

Yes. Prodavac is a masculine noun, so prodavca refers to a male seller / salesman.

If you wanted to refer specifically to a female seller, you would normally use a feminine noun, for example:

• Želim da upoznam prodavačicu.

So the sentence as written points to a male person.

Yes, Serbian word order is fairly flexible because case endings show what each word is doing.

The most neutral order here is:

• Želim da upoznam prodavca.

But other orders are possible for emphasis, for example:

• Prodavca želim da upoznam.

That puts more focus on the seller.

So yes, the order can change, but the given version is the most straightforward and neutral one.

A rough English-friendly approximation is:

• ZHE-lim da oo-POZ-nam pro-DAV-tsa

A few key sounds:

• Ž sounds like the s in measure
• c sounds like ts in cats

So:

• Želim starts with a zh sound
• prodavca ends with -tsa

Serbian spelling is quite phonetic, so words are usually pronounced close to how they are written.

Yes. Serbian commonly uses both Latin and Cyrillic scripts.

In Cyrillic, the sentence is:

• Желим да упознам продавца.

It means exactly the same thing as the Latin-script version:

• Želim da upoznam prodavca.