The next step is typically a Multi-Engine Command Instrument Rating (ME/CIR) which can lead to charter work or regular freight runs.
After you have gained more experience, you may be in a position to apply for regional airlines or national airlines. Pilots wishing to apply for these positions typically have their Air Transport Pilot’s Licence (ATPL).
More information on Virgin entry requirement is available from https://www.virginaustralia.com/au/en/about-us/careers/flight-crew-pilot-recruitment/#overview
More information on Qantas entry requirements is available from the Qantas Careers website.