Union apprenticeship sign-ups near Phoenix - 2 months and counting

I heard of an apprenticeship with paid on-the-job training for people changing careers. I do not usually post, so bear with me. Applications close in 7 weeks. What do you wish you had known?

Thanks for writing this out. I went through something close to it 2 months ago, and it got easier once I kept a simple log of every call and form.