Έχοντας αφήσει το κινητό στο σπίτι, ένιωσα περίεργα στην αρχή, αλλά μετά ηρέμησα.

It means having left.

This is a very common Greek way to show that one action happened before the action in the main clause.

• Έχοντας = having
• αφήσει = left

So:

• Έχοντας αφήσει το κινητό στο σπίτι = Having left my phone at home

The idea is: first I left the phone at home, then I felt strange.

It is a participial construction.

• έχοντας comes from έχω = to have
• αφήσει is the form used after έχω / έχοντας to express a completed action

Together, έχοντας + [verb form] often means having done something.

Examples:

• Έχοντας φάει = having eaten
• Έχοντας τελειώσει = having finished
• Έχοντας αφήσει = having left

You do not need to translate it word-for-word as having have left. As a whole, it simply means having left.

They are close in meaning, but not exactly identical in style.

• Έχοντας αφήσει... is a bit more compact and slightly more written or narrative in tone.
• Αφού άφησα... is often more straightforward in everyday speech.

Both can mean something like:

• After leaving my phone at home
• Having left my phone at home

But αφού can sometimes sound more explicitly like after or even since/because, depending on context, while έχοντας αφήσει focuses on the earlier completed action.

Because Greek usually does not need subject pronouns when the verb already shows the person.

Here:

• ένιωσα = I felt
• ηρέμησα = I calmed down

Both endings clearly show first person singular, so εγώ is unnecessary unless you want emphasis.

So Greek normally prefers:

• ένιωσα περίεργα rather than
• εγώ ένιωσα περίεργα

Yes, normally it does.

In this sentence, the person who left the phone at home is the same person who felt strange and then calmed down.

So the structure implies:

• I, having left the phone at home, felt strange...

If the subject were different, Greek would usually use a different structure to avoid confusion.

Το κινητό means the mobile phone / cellphone.

In everyday Greek, κινητό is very often used by itself as a short form of:

• κινητό τηλέφωνο = mobile phone

So:

• άφησα το κινητό στο σπίτι = I left my phone at home

Even though Greek literally says the phone, English often translates it as my phone when the owner is obvious from context.

Because στο is the contraction of:

• σε
  • το = στο

So:

• στο σπίτι literally = in/to the house
• very often, in context, it simply means at home

This is one of the most common contractions in Greek:

• στο = σε το
• στη = σε τη
• στην = σε την

In this sentence, στο σπίτι is best understood as at home.

Because Greek often uses an adverb-like form after verbs of feeling.

So:

• νιώθω καλά = I feel well
• νιώθω άσχημα = I feel bad
• νιώθω περίεργα = I feel weird / strange

Here, περίεργα is the natural idiomatic choice.

You can also hear:

• ένιωσα περίεργος if the speaker is male
• ένιωσα περίεργη if the speaker is female

But ένιωσα περίεργα is very common when talking about a general strange feeling, more like I felt weird.

Ένιωσα is the aorist form of νιώθω.

Here the aorist shows a complete event in the past:

• ένιωσα περίεργα = I felt weird

It does not mean the feeling lasted forever; it simply presents it as a past experience or moment.

If Greek used an imperfect form instead, it would sound more like an ongoing background state:

• ένιωθα περίεργα = I was feeling weird / I felt weird for a while

But in your sentence, the aorist fits well because the speaker is narrating the sequence of events.

This gives a clear contrast over time:

• στην αρχή = at first / in the beginning
• αλλά μετά = but then / but afterwards

So the meaning is:

• first, I felt strange
• later, I calmed down

This kind of time contrast is very common in Greek storytelling.

Ηρέμησα is also an aorist verb, from ηρεμώ = to calm down / become calm.

It shows a completed change of state:

• μετά ηρέμησα = then I calmed down

The sentence presents the calming down as something that happened after the initial strange feeling.

If you said:

• ηρεμούσα that would suggest an ongoing process in the past, more like I was calming down, which is not the main point here.

Because the opening phrase Έχοντας αφήσει το κινητό στο σπίτι is an introductory participial phrase.

The comma helps separate:

1. the background circumstance
2. the main action

So Greek punctuation works much like English here:

• Having left my phone at home, I felt strange at first...

The comma makes the sentence easier to read and shows where the main clause begins.

Yes. Greek word order is fairly flexible.

The given version is very natural:

• Έχοντας αφήσει το κινητό στο σπίτι, ένιωσα περίεργα στην αρχή, αλλά μετά ηρέμησα.

But Greek could rearrange parts for emphasis, for example:

• Στην αρχή ένιωσα περίεργα, αλλά μετά ηρέμησα, έχοντας αφήσει το κινητό στο σπίτι.

That version is less natural in this context, though, because the opening participial phrase works best before the main clause.

So the original word order is the smoothest and most idiomatic one.