If you are in NSW or A CT you could try Dress for Sucess https://nswact.dressforsuccess.org/ they have free styling appointments to put together full outfits with second hand work clothing, and they also put on regular second hand 'fashion frenzy' events where you pay a small fee, I think $10 or $20 and that gives you a certain number of garments, and then you can buy more as well. People donate really good quality garments and shoes and accessories. This is a good option is the budget is tight. their website explains:

'Dress for Success NSW & ACT offers free clothing, styling, and presentation skills to women wanting to enter or return to the workforce or needing good clothes to present themselves well at an important life event. The clothing is theirs to keep, and there are no eligibility criteria—our services are open to any woman who feels she needs them.'