Union apprenticeship sign-ups near Sacramento after 3 years as a mechanic

I heard of an apprenticeship with paid on-the-job training for people changing careers. It has been a long 21 weeks. The application needs a diploma or equivalent, a driver's licence and a short aptitude test. What do you wish you had known?

You earn while you learn, but the first year is tight. Plan your budget carefully.

The aptitude test was mostly maths and reading a diagram. Free practice tests online were enough for me.