The Chinese make up a majority of the population in Macau, while Macanese and Portuguese make up the rest. The official language here is Cantonese but Hokkien, Mandarin and different Chinese dialects are not uncommon, although much rarer. English is not very commonly used, although there are pockets where it may be understood to a fair extent by locals and spoken as well. In terms of religion, the Macau society is predominantly Buddhist with Catholics making up about 15% of the populace.
Brushing up on the language before you get here is a good idea because communicating what you need or getting directions can be quite a hassle if you can converse only in English. Keep in mind that it is surprisingly easy to get lost in the winding streets of Macau. There may be long lines for ferry rides and sight-seeing spot entries, so make sure you are prepared for a wait. Another thing to remember is to keep plenty of change ready at hand because changing your big notes can be a time consuming and practically an impossible task here.