Union apprenticeship sign-ups near Milwaukee - 13 weeks in

I heard of an apprenticeship with paid on-the-job training for people changing careers. This is my first time dealing with any of this. Classes are in the evening and work is during the day. How hard is the test?

Visit the training centre in person if you can. Seeing the classrooms helped me decide.

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