do i still have time to apply for a visa to hongkong?

I have no idea. Those who are from the certain countries and required to apply have to wait for four to six weeks. I think you'd better consult with the HK Immigration Department immediately.

need to apply for it in advance.

Hong Kong currently does no require a visa if you have a US Passport, but mainland China does require a visa. You can get a travel visa for mainland China from the Chinese Consulate Office, located in most major US cities. You will need your passport to visit HK. Visa requirements may change so check well before you book your trip.