Si todo sale bien, el verano que viene volveremos al mismo destino, porque todavía nos queda mucho por ver.

In Spanish, after si for a real, likely condition, you normally use the present tense, not the future.

So:

• Si todo sale bien = If everything goes well
• not Si todo saldrá bien

This is a very common pattern:

• Si tengo tiempo, voy. = If I have time, I’ll go.
• Si hace buen tiempo, iremos a la playa. = If the weather is good, we’ll go to the beach.

The future tense usually appears in the main clause, not the si clause:

• Si todo sale bien, volveremos...

Literally, sale bien means something like comes out well or turns out well, but in this context the natural meaning is:

• everything goes well
• everything works out

The verb salir has several meanings, and this is one of its very common idiomatic uses:

• La comida salió bien. = The meal turned out well.
• El plan salió mal. = The plan went wrong.

So Si todo sale bien is a fixed, natural way to say If all goes well.

Because it is conjugated for todo, which is grammatically third person singular.

• todo = everything
• sale = it goes / it turns out

So:

• todo sale bien = everything goes well

This is the present tense of salir:

• yo salgo
• tú sales
• él/ella/usted sale
• nosotros salimos
• vosotros salís
• ellos/ellas/ustedes salen

It means next summer.

Literally, it is the summer that comes, but Spanish often uses this structure to talk about the next upcoming time period:

• la semana que viene = next week
• el mes que viene = next month
• el año que viene = next year
• el verano que viene = next summer

This is extremely natural in everyday Spanish.

Yes. El próximo verano also means next summer.

So both are correct:

• el verano que viene
• el próximo verano

In everyday speech, el verano que viene often sounds especially natural and conversational. There is no major meaning difference here.

Volveremos is the future tense of volver.

• volver = to return / to go back
• volveremos = we will return / we will go back

So:

• el verano que viene volveremos = next summer we will return

The future is formed by adding endings to the infinitive:

• volver + emos = volveremos

Other examples:

• viajaremos = we will travel
• iremos = we will go
• veremos = we will see

Because volver here is followed by a when it means to return to a place.

• volver a un lugar = to return to a place

So:

• volveremos al mismo destino = we will return to the same destination

And al is just the contraction of a + el:

• a + el = al

Examples:

• Voy al hotel. = I’m going to the hotel.
• Volvemos al pueblo. = We’re returning to the town.

Mismo means same here.

• el mismo destino = the same destination

It agrees with the noun:

• el mismo lugar
• la misma ciudad
• los mismos sitios
• las mismas playas

So al mismo destino means to the same destination.

Here todavía means still.

• todavía nos queda mucho por ver = we still have a lot left to see

Depending on context, todavía can sometimes translate as yet, but in this sentence still is the best choice.

Examples:

• Todavía estoy cansado. = I’m still tired.
• ¿Todavía no has comido? = Haven’t you eaten yet?

So the exact English translation depends on the sentence.

Literally, nos queda means something like remains to us or is left to us, but natural English is:

• we have left
• there is left for us

So:

• todavía nos queda mucho por ver = we still have a lot left to see

This structure is very common in Spanish:

• Me queda un examen. = I still have one exam left.
• Nos quedan dos días. = We have two days left.
• Te queda mucho por aprender. = You still have a lot left to learn.

Because the verb agrees with mucho, which is treated here as a singular quantity.

• mucho = a lot
• queda = is left

So:

• nos queda mucho por ver = we have a lot left to see

Compare:

• Nos queda mucho trabajo. = We have a lot of work left.
• Nos quedan muchas cosas. = We have many things left.

If the subject is plural, then you use quedan:

• Nos quedan muchos sitios por visitar.

Nos means to us / for us.

In this kind of sentence, Spanish often uses an indirect object pronoun:

• me queda = I have left
• te queda = you have left
• le queda = he/she has left
• nos queda = we have left
• os queda = you all have left
• les queda = they/you all have left

So nos queda mucho por ver literally means:

• a lot remains for us to see

But the natural English translation is:

• we still have a lot left to see

Mucho por ver means a lot to see or more literally a lot left to see.

The structure is:

• mucho / algo / nada + por + infinitive

It expresses something that remains to be done.

Examples:

• Tengo mucho por hacer. = I have a lot to do.
• Hay mucho por cambiar. = There is a lot to change.
• Queda poco por decir. = There is little left to say.

So in your sentence:

• nos queda mucho por ver = we have a lot left to see

Because por + infinitive in this pattern means left to do or remaining to do.

• mucho por ver = a lot left to see

If you used para ver, it would usually suggest for seeing or in order to see, which is a different idea.

Compare:

• Tengo mucho por leer. = I have a lot left to read.
• Necesito gafas para ver bien. = I need glasses to see well.

So in this sentence, por is the correct preposition.

Here destino means destination, especially in a travel context.

• volveremos al mismo destino = we’ll go back to the same destination

Be aware that destino can also mean fate in other contexts:

• El destino quiso que... = Fate wanted that...
• Creo en el destino. = I believe in fate.

But in a sentence about summer travel, destination is clearly the intended meaning.

Yes, Spanish word order is flexible, although the original sentence is very natural.

Original:

• Si todo sale bien, el verano que viene volveremos al mismo destino, porque todavía nos queda mucho por ver.

You could also say:

• El verano que viene, si todo sale bien, volveremos al mismo destino...
• Volveremos al mismo destino el verano que viene, si todo sale bien...

The original order works well because it introduces:

1. the condition: Si todo sale bien
2. the time: el verano que viene
3. the main action: volveremos
4. the reason: porque todavía nos queda mucho por ver

So it sounds balanced and natural.

Yes. Porque means because and introduces the reason for returning.

• volveremos al mismo destino = we’ll return to the same destination
• porque todavía nos queda mucho por ver = because we still have a lot left to see

So the full logic is:

• If everything goes well, we’ll go back next summer, because there is still a lot we haven’t seen.

A useful reminder:

• porque = because
• por qué = why
• porqué = the reason / the motive
• por que = a less common combination in other structures

Yes, it sounds very natural in Spain.

Several parts are especially common in everyday Spanish from Spain:

• Si todo sale bien
• el verano que viene
• volveremos al mismo destino
• todavía nos queda mucho por ver

Nothing in the sentence sounds strange, overly formal, or unnatural. It is a very idiomatic, standard sentence.