Recommended beauty courses (skin focused), online or in Sydney?

Hiya, apologies if this is in the wrong category but I wasn’t sure where to best put it! I work in retail beauty, mostly in skincare, and want to get some extra training in my own time to take my skills further. There are sooo many beauty therapy courses but I want to do one which focuses on skin. Any suggestions for places online or in Sydney to check out or avoid?