When do we use "arrive at" versus "arrive in"?

Arrive carries 3 prepositions: in, on, or at.

1. He arrived in New York.
2. He arrived at the station.
3. He arrived on the scene of the accident.

Also:

• He arrived here. [no preposition]
• He arrived at 12 o'clock.
• He arrived within 10 minutes.
• He will arrive in an hour.

So it turns out that 'arrive' either carries or doesn't carry a preposition depending on the place or time that follows it, i.e. if the place or the time carries a preposition.

For time:

'at' with a specific point in time = "I will arrive at 4:30"

'in' with a period of time = "I will arrive in 30mins"

Confusingly it's 'on' with a day = "I will arrive on tuesday"

For places:

'in' with general areas, countries, cities etc. = "I will arrive in Italy", "I will arrive in Rome"

'at' with specific places = "I will arrive at your house", "I will arrive at the airport"

You can use also use 'in' with a specific place if you mean specifically inside.
"I will meet you at the shop", could be waiting outside - but "I will meet you in the shop" means I will be inside.