Minä lähden kotoa aikaisin aamulla.

Yes. In Finnish, the verb ending already shows the subject:

• lähden = I leave / I’m leaving

So minä is often omitted unless you want emphasis, contrast, or extra clarity.

• Lähden kotoa aikaisin aamulla. = neutral, very natural
• Minä lähden kotoa aikaisin aamulla. = I leave home early in the morning, maybe with a slight emphasis on I

Lähden is the 1st person singular present tense of lähteä, meaning to leave or to set off.

So:

• lähteä = to leave
• lähden = I leave / I’m leaving

Finnish present tense often also covers what English expresses with the future, especially when there is a time expression:

• Minä lähden kotoa aikaisin aamulla. can mean
  
  • I leave home early in the morning
  • I’m leaving home early in the morning

Because lähteä focuses on the idea of departing from a place, while mennä focuses more on going somewhere.

• lähden kotoa = I leave home
• menen kotiin = I go home

In this sentence, the important idea is the starting point: from home. That makes lähden the natural choice.

Because kotoa means from home.

Finnish often expresses ideas like from, in, and to by changing the ending of the noun instead of adding a separate preposition.

With koti:

• koti = home
• kotona = at home
• kotoa = from home
• kotiin = to home / homeward

So in this sentence:

• lähden kotoa = I leave from home

This is one of those common Finnish word forms that you mostly learn as a set:

• koti
• kotona
• kotoa
• kotiin

The change is not completely obvious from English, and learners usually memorize these as fixed everyday forms. The important thing is:

• kotoa = from home

You may also see more regular-looking forms like kodista, but kotoa is the normal idiomatic choice for from home in everyday Finnish.

Aikaisin is an adverb meaning early.

So:

• aikaisin = early

It tells you how early / at what part of the time period the action happens.

In the sentence:

• aikaisin aamulla = early in the morning

Because they do slightly different jobs:

• aamulla = in the morning
• aikaisin = early

Together they give a fuller time expression:

• aikaisin aamulla = early in the morning

If you removed one:

• lähden kotoa aamulla = I leave home in the morning
• lähden kotoa aikaisin = I leave home early

With both, the sentence is more specific.

Aamulla is the adessive form of aamu (morning).

In Finnish, the -lla / -llä ending is often used in time expressions to mean something like during / at / in a time period.

So:

• aamu = morning
• aamulla = in the morning

Other common examples:

• illalla = in the evening
• yöllä = at night
• päivällä = during the day

Grammatically, it is present tense.

But in Finnish, the present tense is very often used to talk about the future, especially when the sentence already includes a time expression like aamulla.

So this sentence can mean either:

• a habitual action: I leave home early in the morning
• a future plan: I’m leaving home early in the morning

Context tells you which one is meant.

No, Finnish word order is fairly flexible. The basic sentence is natural as written:

• Minä lähden kotoa aikaisin aamulla.

But you can move parts around for emphasis or style. For example:

• Aamulla minä lähden kotoa aikaisin.
• Kotoa minä lähden aikaisin aamulla.

These are possible, but the emphasis changes. The original version is a very neutral, straightforward way to say it.

No. Finnish does not have articles like English a and the.

So:

• kotoa just means from home
• aamulla just means in the morning

Finnish leaves that kind of definiteness to context, instead of using separate words like a or the.

Yes. On its own, it can describe either:

1. a habit / routine
   
   • I leave home early in the morning
2. a specific future event
   
   • I’m leaving home early in the morning

Finnish often allows both readings in the present tense. Context decides which one is intended.