Best thing to do is do a pre app, 3months see how you like it, you will meet all the dickheads at tafe so you will get a taste of the kinda people you have to work with lol i was a motor mechanic and loved it tho in time it ruined my hobby working on my cars etc and was low on cash which kinda sux when you wanna upgrade mods and so on.. so i took a break... its really hard to find a job as it is a male dominated trade unfortunately, it took me 1yr to find a diesel app so i gave up had enough of all the time wasting and a big factor is ppl around you being negative like some of the posts above. My mate told me to go for a interview at a wshop that was hiring and i said ok last one, i got the job and now im an app absolutley love it, pays better and working on trucks is different to cars!! I actually look foward to go to work haha but just remember your hands will b stuffed cuts, grease seems to live under your nails 24/7, cant wear white, allways covered in black sht, dont mind lifting heavy things and coping shit off ppl at work.
if your really egar go for it dont let anyone talk you out of it.
good luck