Trades apprenticeship applications open in Boston - what worked for you?

The training centre near Boston opened applications for apprenticeships in electrical and welding trades. This is my first time dealing with any of this. The application needs a diploma or equivalent, a driver's licence and a short aptitude test. What do you wish you had known?

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

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