Chcę napić się herbaty po pracy.

Napić się means to drink some / to have a drink, usually with the idea of completing the action or satisfying a need. It is the perfective partner of pić.

• pić = to drink, to be drinking, to drink in general
• napić się = to drink some, to have a drink, to drink up / enough

So:

• Chcę pić. = I am thirsty / I want to drink.
• Chcę napić się herbaty. = I want to have some tea.

In this sentence, napić się sounds more natural because the speaker means having some tea, not just the general activity of drinking.

In napić się, się is part of the verb expression. You should learn napić się as a whole unit.

It does not literally mean oneself here in the way English learners might expect. Instead, it is simply required by this verb form.

So:

• napić się = to have a drink / to drink some
• not just napić

Many Polish verbs include się, and often the best approach is to memorize them together with it.

Because napić się normally takes the genitive case, and the genitive of herbata is herbaty.

Cases here:

• herbata = nominative
• herbatę = accusative
• herbaty = genitive

After napić się, you usually use genitive for the thing being drunk:

• napić się wody = drink some water
• napić się kawy = have some coffee
• napić się herbaty = have some tea

This often gives a some amount of feeling in English.

Because chcę means I want, and in Polish, as in English, the conjugated verb often comes first in this kind of structure:

• Chcę napić się herbaty. = I want to drink some tea.

Here:

• chcę = I want
• napić się = to drink some / have a drink
• herbaty = tea
• po pracy = after work

This is a very standard and natural word order.

Chcę is the 1st person singular form of chcieć (to want).

So:

• chcę = I want
• chcesz = you want
• chce = he/she/it wants
• chcemy = we want
• chcecie = you all want
• chcą = they want

In this sentence, chcę clearly tells you the subject is I, so Polish does not need the pronoun ja.

Because Polish usually omits subject pronouns when the verb already shows who the subject is.

• Chcę already means I want
• so Ja chcę napić się herbaty is possible, but ja is usually added only for emphasis, contrast, or clarity

For example:

• Chcę napić się herbaty. = neutral
• Ja chcę napić się herbaty, nie kawy. = I want tea, not coffee

Po pracy means after work.

The preposition po often requires the locative case, and the locative of praca is pracy.

So:

• praca = work
• po pracy = after work

Other examples:

• po obiedzie = after lunch
• po szkole = after school
• po filmie = after the movie

So po pracy is a set phrase meaning after work / after finishing work.

Yes, but the tone is different.

• po pracy = neutral, standard, very common
• po robocie = more colloquial, informal, sometimes a bit more casual or regional in feel

So in a basic textbook-style sentence, po pracy is the safest and most standard choice.

Yes, Polish word order is more flexible than English, but different orders can sound more natural depending on emphasis.

The neutral version is:

• Chcę napić się herbaty po pracy.

You could also say:

• Po pracy chcę napić się herbaty.
  This emphasizes after work a bit more.

Both are correct, but the original version is a very natural default.

In this sentence, herbaty most naturally means some tea or a bit of tea, not tea as an abstract concept.

That is because napić się + genitive often suggests taking some amount of something:

• napić się wody = drink some water
• napić się kawy = have some coffee
• napić się herbaty = have some tea

English often leaves some unstated, but the idea is still there.

A rough pronunciation guide is:

• Chcę ≈ h-tsen
• napić się ≈ NA-pich shyeh
• herbaty ≈ her-BA-ti
• po pracy ≈ po PRA-tsi

A few useful notes:

• ch sounds like a strong h
• ę is a nasal vowel, but before some consonants it may sound closer to en/em
• ć is a soft ch-like sound
• się is pronounced roughly shyeh
• c in pracy sounds like ts

A more natural full approximation: H-tsen NA-pich shyeh her-BA-ti po PRA-tsi

It can, depending on context, but the form napić się often makes it sound like a specific desired action: I want to have some tea after work.

If you wanted a more general or habitual idea, Polish might use other wording, for example:

• Lubię pić herbatę po pracy. = I like drinking tea after work.
• Zwykle piję herbatę po pracy. = I usually drink tea after work.

So your sentence most naturally expresses a present wish or intention.

Yes. This is a very useful pattern:

Chcę napić się + genitive noun + po pracy.

Examples:

• Chcę napić się kawy po pracy. = I want to have some coffee after work.
• Chcę napić się wody po pracy. = I want to drink some water after work.
• Chcę napić się soku po pracy. = I want to have some juice after work.

Just remember that the noun after napić się should normally be in the genitive.