@jjenniefer I suppose the pathway to choose depends on how soon you want to move to Australia and what job/occupation you want to do once you get there. Considering your current work experience in admin and customer service, it might be a little challenging (in my opinion lang ha) for you to migrate with that occupation right now because it's not management level.
Going for the student route is popular because it's a good way to upskill (increase/upgrade your skill set) towards the occupation you want (and working part-time--hopefully in the same industry as your studies--would help you in gaining local work experience). Meanwhile, directly applying for PR visa requires a solid work experience in the job you want to do (and is in demand) in Australia, as well as a lot of money and preparation (skills assessment, visa fee, etc).
Is it your long-term plan to work in the admin/customer service industry? Or are you planning to use your work experience to migrate first then change industry after getting PR?
Do you think with your current profile, you can make the best application possible for PR? Or do you think having Australian qualifications might improve your odds of getting that PR visa?
If you intend to continue with the admin/customer service path, I'd recommend you take the student route, perhaps a degree in management or business, then find a managerial job. Then you can nominate a management-level occupation when you apply for PR. The student route is actually more expensive and time-consuming than applying directly for a PR visa, but if you can score a scholarship from the university (VET schools don't have that many scholarship options, but most unis do), you have one less thing to worry about when it comes to expenses. Since you're still in the research stage, look for universities that offer the course you want and the scholarships available. Seriously, in comparison to the UK, US, and Canada, I feel that Australia offers a lot more scholarships than other countries. You just need to be diligent in looking for scholarship opportunities. ๐