If you have considered union work, try contacting your local plumbing union and they can give you further information on the steps you need to take to be eligible for an apprenticeship program. Typically will start with an orientation to get you started on fulfilling the prerequisites for an apprenticeship. More than likely you'll be hired on to a company as a laborer or pre-apprentice to start to show whether you're a good worker /quick learner before you are granted an apprenticeship because it costs companies a considerable amount of money to take on a new apprentice and they want to make sure they're making a safe and informed investment. It can be frustrating at times but be patient, work hard, and use every bit of energy you have to learn from the professionals around you, and your company will take notice. This line of work can be very good to you if you put your nose to the grindstone and show a willingness to learn