Usually in china the odd numbers are considered more lucky - this is why most pagodas have 3, 5, 7, or 9 levels.
4 is considered unlucky in nearly every asian culture - this is due to the pronunciation being very similar to the word for death. In some places in the east you will not see a 4th floor of a building similar to not seeing a 13th floor in some places in the west.
I’ve not heard of any specific connotation related to eight, although most (but not all) pronunciations, ba, are similar to the word for father, ba or pa.
Yes, 8, 18 lucky according to Chinese