Við förum héðan eftir tíu mínútur.

Yes:

• Við = we
  This is the nominative form, because it is the subject of the sentence.

• förum = go / are going / leave
  This is the 1st person plural present-tense form of fara (to go).

• héðan = from here
  This is an adverb of movement away from a place.

• eftir tíu mínútur = in ten minutes / after ten minutes
  Here it means ten minutes from now.

So the structure is basically:

We + go/leave + from here + in ten minutes

That is very normal in Icelandic.

Icelandic often uses the present tense for a planned or near-future action, just as English can say:

• We leave in ten minutes
• We’re leaving in ten minutes

So Við förum héðan eftir tíu mínútur is naturally understood as a future action because of the time expression eftir tíu mínútur.

Literally, fara means to go. But in this sentence, because of héðan (from here), the most natural English meaning is leave:

• Við förum héðan = We’re leaving here / We’re going away from here

So the Icelandic verb is still basically go, but English often prefers leave in this kind of context.

Hér means here, but héðan means from here.

Icelandic often uses special adverbs to show location vs movement:

• hér = here
• hingað = to here / сюда-type meaning
• héðan = from here

So:

• Við erum hér = We are here
• Komdu hingað = Come here
• Við förum héðan = We’re leaving from here

Usually, no—not in natural Icelandic.

Icelandic normally prefers the single adverb héðan for from here. Using frá hér sounds unnatural in ordinary speech.

So the idiomatic choice is:

• héðan = from here

not usually:

• frá hér

This is because of a common vowel change in Icelandic called u-umlaut.

The verb is:

• fara = to go

But in the við form, the ending is -um, and that u affects the stem vowel:

• fara → förum

So the a changes to ö before a following u in the next syllable.

This kind of change happens in many Icelandic words and forms, so it is something learners get used to over time.

Here it means in ten minutes, that is, ten minutes from now.

Word-for-word, English learners often notice that eftir can look like after, and that is not wrong. But in this sentence, the natural English meaning is:

• We’re leaving in ten minutes

rather than a stiff literal version like:

• We’re leaving after ten minutes

So in this kind of time expression, eftir + time span often corresponds to English in + time span.

Because the sentence refers to ten minutes, so the noun has to be plural.

• mínúta = minute
• mínútur = minutes

Since tíu means ten, the plural is required:

• tíu mínútur = ten minutes

Because eftir can take different cases depending on meaning, and in this time-expression use, it takes the accusative.

So here:

• eftir tíu mínútur = in / after ten minutes

The noun phrase is in the accusative plural, and for mínúta the accusative plural form is:

• mínútur

not:

• mínútum (which is dative plural)

This is a good example of why prepositions in Icelandic must often be learned together with the case they require in each meaning.

Yes. Icelandic word order is flexible, but there are rules.

The original sentence:

• Við förum héðan eftir tíu mínútur

You can also say:

• Eftir tíu mínútur förum við héðan

This is very natural and puts more focus on the time.

Notice what happens: when Eftir tíu mínútur comes first, the verb förum still comes next. That is because Icelandic normally follows a verb-second pattern in main clauses.

So:

• Við förum ...
• Eftir tíu mínútur förum við ...

are both good, but:

• Eftir tíu mínútur við förum ...

is not correct standard word order.

Yes, you could, and it would mean something like We will leave here in ten minutes.

But in everyday Icelandic, the simpler present-tense version is often more natural:

• Við förum héðan eftir tíu mínútur

Using munu to make an explicit future is possible, but it can sound more formal, more emphatic, or less conversational depending on context.

So for a simple planned future, the original sentence is usually the most natural choice.