I live in sydney so hit me up when u get here. Where are you staying when your here?
Beaches are everywhere id just avoid bondi.
Closest skiing is thredbo or perisher which are next to eachother and its about 4.5 hours drive. I go down most weekends so if you want to share some fuel money. season is from june - october.
Heaps of good night life in sydney but its pretty pricey. there are a few cheap places if you know where to look.