I say absolutely go for it. Time goes by fast, if you don't do this in a few years you could very well still be kicking around in a dead end job while at the same time you could be a journeyman electrician. Not sure about Australia but here in the U.S. a building trades apprenticeship program is a union operation and the work will be mostly commercial construction which is good clean work, not crawling around in attics, 7 to 330 with plenty of breaks.
I became a plumbing/HVAC man at 22 after military service, I tried to get into an apprenticeship but they wouldn't have me so I found work and mostly taught myself then after 7 years I became a contractor. When you learn a skill no one can take it from you. If you have no special skill or trade and work your way up into a position you could just be fired and have to start all over again.
Understand that in the building trades there is a timeline, when you are young you will work hard repetitive manual labor and by the time you are about 50 your body will be worn out so you will be transitioning to supervisory type positions. Starting at 29 just avoids 10 years of abuse on the body

at 50 you won't be as broken down as your coworkers