Transport: There are some trains in Vietnam, but mostly people use sleeper bus or tourist buses. Be warned that the driving can be crazy! I use 12GoAsia or Bookaway to book my domestic transfers.If you’re in a city – use Grab!
Currency: Vietnamese Dong. They are really large so a lot of places abbreviate to the thousand e.g. 500,000 dong = 500k dong. 25,000 dong ~ 8 HKD, 10,000 dong ~ 0.4 USD
Sim card: Vietel is a frequently used telecom company, and you need your passport to buy a sim card in Vietnam. You might want to preorder your sim so you can use Grab from the taxi.
Language: Language: Vietnamese, Xin Chow means hello, Cam Yan