AMB is consistently active at the moment as a support base for the Talisman Exercise at Shoalwater - with a fair bit of activity.
Inbound via MLY will keep you clear of all that and if you stay in CTA you can request a vector towards TV towers.
Usually coming from AMB ATC expect you to be OCTA by the edge of MCTA - which is 3500 at the AMB/BN boundary and 1500 by Goodna. If the weather is marginal the RAD/NDB basically mirrors the AMB-AF track.
If unfamil just say so and you will get all the help you need from Brisbane Radar or Approach.
In VMC conidtions IFR aircraft are treated exactly the same as VFR - the only time you will get an IAL or Instrument Departure for AF is in IMC (or at night on Departure when AF is active - it closes at 1800 local, which currently is after last light - 1722 this week roughly)