G'day mate... good on ya for being proactive and making an effort to learn outside work and not just hitting the piss (yeah Aussie here) That shows a bit of initiative and drive and seems like the boss made a good choice frankly, especially at your age.
The whole point to your apprenticeship is to learn and all will come in good time but being a specialised part of a larger process it might be an idea to read about commercial print and there's a few books out there like this but that is way more than you need really. Also your states OH&S and award too so ya across everything I reckon.
Bought this book at Drupa many years ago, but I believe it's updated. It covers everything.
Second link below is a pdf of the start of the book and the contents.
https://www.amazon.co.uk/Handbook-Print-Media-Technologies-Production/dp/3540673261/ref=sr_1_2?adgrpid=54075308395&gclid=EAIaIQobChMIn_L17M6Q9wIVUuvtCh3OywAWEAAYASAAEgJwD_D_BwE&hvadid=259043747454&hvdev=c&hvlocphy=1006524&hvnetw=g&hvqmt=e&hvrand=18222544322143517910&hvtargid=kwd-299389250333&hydadcr=24430_1748944&keywords=handbook+of+print+media&qid=1649838370&sr=8-2
https://link.springer.com/content/pdf/bfm%3A978-3-540-29900-4%2F1.pdf