A la salida del teatro, hablamos un rato en la plaza.

Not usually. In this sentence, a la salida de + place/event is a common expression meaning something like:

• when leaving
• on the way out of
• after coming out of

So A la salida del teatro means when we came out of the theatre or after the theatre, as we were leaving.

Literally, salida is exit or way out, but in this structure it often refers to the moment of leaving, not just the physical door.

For example:

• A la salida del cine, fuimos a cenar. = After coming out of the cinema, we went to dinner.

Because de + el contracts to del in Spanish.

So:

• de + el teatro → del teatro

This is mandatory in normal Spanish, except when el is part of a proper name, such as:

• de El Escorial
• de El Greco

But with ordinary nouns like teatro, you must use del.

Spanish often leaves out subject pronouns because the verb ending already shows who the subject is.

Here, hablamos tells you the subject is we.

So both are possible:

• Hablamos un rato en la plaza.
• Nosotros hablamos un rato en la plaza.

But the version without nosotros is more natural unless you want extra emphasis or contrast, for example:

• Nosotros hablamos, pero ellos se fueron enseguida.
  = We talked, but they left straight away.

It can mean either, because the nosotros form of the present and the preterite is the same in many -ar verbs.

So hablamos can be:

• we talk / we are talking (present, depending on context)
• we talked (preterite)

In this sentence, the context strongly suggests the preterite meaning: we talked. The phrase A la salida del teatro sounds like a completed past event in a story.

This is very common in Spanish: context tells you which tense is meant.

Un rato means a while or for a bit.

So:

• hablamos un rato = we talked for a while

It does not give an exact amount of time. It is just a natural, everyday way to say the action lasted some time.

Similar expressions:

• esperé un rato = I waited a while
• descansamos un rato = we rested for a bit

Because en is used for location, while a usually indicates movement toward a destination.

Here, the sentence says where the talking happened:

• en la plaza = in the square / at the square

If the sentence were about going there, then a would be used:

• Fuimos a la plaza. = We went to the square.

But once you are already there and something happens there, Spanish normally uses en:

• Hablamos en la plaza.
• Nos sentamos en la plaza.

The comma separates the introductory time/circumstance phrase from the main clause.

So the sentence is structured like this:

• A la salida del teatro, = introductory phrase
• hablamos un rato en la plaza. = main clause

In English, we often do the same:

• After leaving the theatre, we talked for a while in the square.

The comma is especially natural when the sentence begins with a longer phrase that sets the scene.

Spanish uses definite articles more often than English does.

In this sentence:

• la salida = the exit / the way out / the moment of leaving
• del teatro = of the theatre
• la plaza = the square

Even when English might say something more general, Spanish often prefers the article.

For example:

• a la salida del teatro sounds natural in Spanish
• English might say after the theatre or when leaving the theatre, without matching every article exactly

So it is best not to translate articles too mechanically. Spanish and English do not always use them in the same way.

Not exactly. In Spain, plaza usually means a public square or town square, not a shopping centre or commercial plaza.

So en la plaza here most likely means in the square or at the town square.

This is a very common cultural vocabulary point, because English plaza can suggest something quite different depending on the variety of English.

Yes. A few natural alternatives are:

• Al salir del teatro, hablamos un rato en la plaza.
• Después del teatro, hablamos un rato en la plaza.
• Cuando salimos del teatro, hablamos un rato en la plaza.

They are all similar, but not identical:

• Al salir del teatro focuses on the act of leaving
• Después del teatro is broader: after the theatre
• Cuando salimos del teatro is more explicit: when we left the theatre

The original A la salida del teatro is a very natural, slightly fixed expression.