Cuando termine la videollamada, quiero pasear un rato por el barrio para desconectar.

Because cuando is referring to a future event here: the call has not finished yet.

In Spanish, when cuando introduces a clause about the future, you normally use the present subjunctive:

• Cuando termine la videollamada... = When the video call ends / has ended...

Compare:

• Cuando termina la videollamada, siempre me siento cansado.
  = When the video call ends, I always feel tired.
  Here it is habitual, so indicative is used.

So in your sentence, termine is present subjunctive because the action is still in the future.

Termine is the present subjunctive form of terminar.

Here, it means:

• (yo) termine
• (él/ella/usted) termine

In this sentence, the subject is actually la videollamada, so the sense is:

• cuando termine la videollamada
  literally: when the video call finishes / ends

Spanish often uses a thing as the subject of a verb in cases like this.

Because Spanish usually doesn’t need subject pronouns unless you want emphasis, contrast, or clarity.

The verb quiero already tells you the subject is I.

So:

• quiero pasear... = I want to go for a walk...

You could say yo quiero, but it would sound more emphatic, like:

• Yo quiero pasear, no quedarme en casa.
  = I want to go for a walk, not stay at home.

Un rato means for a while or a little while.

It is a very common expression in Spanish.

Examples:

• Voy a descansar un rato. = I’m going to rest for a while.
• Hablamos un rato. = We talked for a while.

So pasear un rato means to go for a walk for a while.

They are related, but not exactly the same.

• caminar = to walk
• pasear = to stroll / to go for a walk / to take a walk

Pasear often suggests walking in a relaxed way, often for pleasure or to unwind, not just moving from one place to another.

So in this sentence, pasear fits better because the idea is a pleasant walk to relax.

In Spain, this is very natural.

Yes. That would be very natural too.

• Quiero pasear un rato por el barrio...
• Quiero dar un paseo por el barrio...

Both are common. A small nuance:

• pasear is the verb itself: to stroll / to walk
• dar un paseo is more like to take a walk

Both work well in Spain.

Because por here suggests movement through/around an area.

• pasear por el barrio = to walk around the neighborhood
• estar en el barrio = to be in the neighborhood

So:

• por el barrio focuses on moving around within that area
• en el barrio would sound more static

This is why por is the natural choice with pasear here.

Usually, yes: barrio means neighborhood or district.

In this sentence, el barrio is most naturally the neighborhood where the speaker lives or currently is.

Depending on context, barrio can sometimes refer more broadly to a local area or district of a town or city, but neighborhood is the best basic meaning.

Para means in order to or to, expressing purpose.

So:

• para desconectar = to switch off / to unwind / to disconnect mentally

The structure is:

• para + infinitive

This is used when the subject of both actions is the same:

• quiero pasear... para desconectar
  = I want to walk... in order to unwind

Very common examples:

• Estudio para aprender. = I study to learn.
• Salgo a correr para despejarme. = I go running to clear my head.

Literally, yes, desconectar means to disconnect.

But in Spain, it is also very commonly used in an everyday, figurative sense to mean:

• to switch off
• to unwind
• to mentally disconnect from stress
• to take a break from work or pressure

So in this sentence, it does not mean unplugging something. It means relaxing mentally after the video call.

This figurative use is especially common in Spain.

Because the sentence begins with a subordinate clause:

• Cuando termine la videollamada, ...

In Spanish, when this kind of time clause comes first, it is normal to separate it with a comma before the main clause.

So the structure is:

• [Cuando termine la videollamada], [quiero pasear un rato por el barrio para desconectar].

This is similar to English:

• When the video call ends, I want to go for a walk...

Yes, but with an important distinction.

If you mean a future event, you would normally say:

• Cuando acabe la videollamada...
• Cuando termine la videollamada...

Both are correct.

If you say:

• Cuando acaba la videollamada...

that usually sounds more like a habitual action or general truth, not this specific future moment.

So for this sentence, acabe or termine would fit best.
Terminar and acabar are both common here, though terminar may feel slightly more neutral.

Yes, videollamada is a very common and standard word in Spain.

It means video call.

It is feminine because the main noun is llamada:

• la llamada
• la videollamada

So:

• una videollamada
• la videollamada

This is exactly the sort of word you would hear in everyday modern Spanish.

Not most naturally.

As written, la videollamada is the grammatical subject, so the phrase most naturally means:

• when the video call ends / finishes

If you specifically wanted to say when I finish the video call, you would more clearly say:

• Cuando termine la videollamada yo is not correct
• Cuando termine la videollamada can sometimes be understood that way from context, but it normally sounds like the call itself ends
• clearer options would be:
  • Cuando termine con la videollamada...
  • Cuando acabe la videollamada...
    depending on context

In everyday use, though, the original sentence sounds perfectly natural and people will understand the intended idea.

Because quiero expresses desire/intention, not a definite future plan.

• quiero pasear = I want to go for a walk
• voy a pasear = I’m going to go for a walk

So the original sentence focuses on what the speaker wants to do after the call, rather than simply stating what they will do.

Both are possible, but they mean slightly different things.