The best words to learn is Chuc Mung Nam Moi = Happy New Year !!
Christina’s Language 101
Chuc – as in chook
Mung – it is indescribable as not the way we pronounce anything in English, but like moon, but not.
Nam – come with a N (nome)
Moi – toy with a M (moy)
Vietnamese will appreciate it if you learn this phrase. It is simple and once you learn it I would say it to everyone you come in contact with.