My thoughts, as someone who did the Cert III - albeit over a decade ago and through RMIT, where it was a pilot program and a total shitshow...
Honestly I'd talk to the office on Monday. I suspect the handbook is some bureaucratic nonsense that everyone's 'supposed' to read but no-one does, but ask. Likewise about whether it's worth waiting for the next intake - in my experience the course wasn't academically challenging but very emotionally challenging though that may have been because I was caring for Mum at the time.
Good luck!