how do younger people address older people in this culture/ eg mr or mrs/

Older people are rarely referred to by first names; they are addressed with such honorifics as Mr. and Mrs. or the appropriate non-English equivalents. Sometimes terms such as "Uncle" or "Auntie" are appropriate for older non-relatives. For example, the young people will call an older person as "Ye Ye" (grandfather), and "Nai Nai" (grandmother), "Ah Yi" (aunt), and "Shu Shu" (uncle) as a sign of respect even if that person is not family by blood.