What Vias will I need for Hong Kong & then for entry to Guilin ?

I am an Australian resident.

I am traveling to Hong Kong from Sydney to attend a work confernce for a few days & then plan to go on holidays to Guilin in China for a few days sightseeing then back to Hong Kong.

What Vias will I need for Hong Kong & then for entry to Guilin ?

Also how long does it usually take to get a Visa approved for China via the Sydney CVASC office ?