To enter Hong Kong, you will need a passport that is valid for at least one month beyond the date of your intended stay, adequate funds to cover your stay without working locally, and evidence of onward/return transportation. Many neighboring areas require that your passport is valid for at least six months before they will allow you to enter, so if you plan on regional travel beyond Hong Kong, make sure that your passport is valid for at least six months beyond the date you plan to enter such areas. You do not need a visa for tourist visits of up to 90 days.
You may be granted an extension of your stay if you apply to the Hong Kong SAR Immigration Department. You must have an appropriate visa to work or study in Hong Kong.