Jeg sætter en påmindelse i min mobil, og jeg får også en notifikation, når bussen er forsinket.

Yes. In Danish, sætte is a very common verb for setting something like a reminder, an alarm, or a timer.

So:

• sætte en påmindelse = set a reminder
• sætte en alarm = set an alarm
• sætte et vækkeur = set an alarm clock

It is idiomatic Danish. English uses set, and Danish often uses sætte in the same kind of situation.

They are related, but not the same.

• en påmindelse = a reminder
  Something you set up so you will remember something later.
• en notifikation = a notification
  A message or alert you receive from a phone, app, or system.

So in this sentence:

• first, the speaker sets a reminder
• then, the speaker also receives a notification

Because en påmindelse and en notifikation are indefinite singular nouns, so they take the article en.

But min mobil has a possessive word (min = my), and in Danish, possessives normally replace the article.

So:

• en mobil = a phone
• mobilen = the phone
• min mobil = my phone

You do not say en min mobil.

Both i and på can be used with devices in Danish, but they often give slightly different impressions.

• i min mobil suggests inside the phone / in the phone system / in an app
• på min mobil often suggests on the phone / on the screen / on the device

In this sentence, i min mobil is natural because the reminder is being created within the phone’s system or apps.

This is one of those cases where English on my phone does not map perfectly to just one Danish preposition.

Because the sentence contains two full main clauses:

• Jeg sætter en påmindelse i min mobil
• jeg får også en notifikation

Repeating the subject is completely normal in Danish and often makes the sentence clearer.

You can sometimes leave the subject out in the second clause if it is the same subject, but repeating it is very common and sounds natural.

Because Danish main-clause word order usually puts the finite verb early, and words like også often come after that verb.

So:

• jeg får også en notifikation

This is similar to other adverbs in Danish:

• jeg kommer ikke i morgen
• jeg ser ofte den bus

A useful rule of thumb: in a normal main clause, the finite verb comes early, and adverbs like også often follow it.

Because når here introduces a subordinate clause, and subordinate clauses do not use normal Danish main-clause word order.

So you get:

• når bussen er forsinket

not:

• når er bussen forsinket

The version Når er bussen forsinket? would sound like a question meaning When is the bus delayed?

So after når meaning when, Danish keeps the order:

• conjunction + subject + verb

Because når means when or whenever, while hvis means if.

In this sentence, the idea is:

• the notification comes when the bus is delayed

That sounds like a real trigger or regular situation, not a hypothetical possibility.

Compare:

• Når bussen er forsinket, får jeg en notifikation.
  = Whenever/when the bus is delayed, I get a notification.
• Hvis bussen er forsinket, får jeg en notifikation.
  = If the bus is delayed, I get a notification.

Both are possible in some contexts, but når is very natural when talking about something expected or automatic.

Because bussen means the bus, while en bus means a bus.

Danish usually makes nouns definite by adding the article to the end of the word:

• en bus = a bus
• bussen = the bus

Here, the sentence refers to a specific bus that matters to the speaker, so Danish uses the definite form.

Er forsinket describes the state: the bus is delayed.

• bussen er forsinket = the bus is delayed

Bliver forsinket focuses more on the change or process:

• bussen bliver forsinket = the bus gets delayed / becomes delayed

In this sentence, the notification is about the bus being in the delayed state, so er forsinket is the most natural choice.

In this sentence, it works like an adjective meaning delayed.

So:

• bussen er forsinket = the bus is delayed

Historically, forms like this come from past participles, but for learners it is often easiest to understand forsinket here as an adjective after er.

Yes. Danish often uses the present tense for:

• habits or routines
• scheduled events
• near-future situations

So this sentence can mean something like:

• this is what I usually do
• this is what happens in that situation
• this is my plan right now

That is very normal in Danish, just as English can also use the present in some similar cases.