Capital: Bangkok – a must for street food, temples, and a modern vs old city center.
Transport: Trains, domestic flights, and tourist buses. I use 12GoAsia or Bookaway to book my domestic transfers.If you’re in a city – use Grab!
Currency: Thai baht, cash is king in Thailand! 1 HKD ~ 4 baht, 3 USD ~ 110 baht
Sim card: AIS is the best coverage. If you’re only headed to the cities, True is more value for money. You can also preorder your sim card.
Handy apps: Grab for taxi in city, Klook for tickets and activities
Language: local speaks Thai and most speak a basic level of English. It doesn’t hurt to learn a few phrases: Sawadee ka/krup – ka for girls, krup for men. Kup Khu ka/krup – thank you. Koh Dod ka/krup – sorry