The common way to say "Hello" in Farsi, is "Salam". You can say it in a casual as well as formal context, for any time of the day. In the morning, you can also say "Sobh bekheir", which means "Good morning". In the evening, try saying "Asr bekheir" for "Good evening" Listen to the podcast to see how to say "What's your name" in Farsi :)