Get hired as a groundworker first
Best if You need income now and want to learn the work from the ground up.
Utilities and line contractors hire entry level ground crew who load material, dig holes, set poles and pass tools to lineworkers. Alexander City, Alabama, for example, describes its groundman job as the entry point in the line of progression for lineman, with a high school diploma or GED and a CDL within six months.
Ground work alone does not make you a lineworker. Ask whether the employer moves ground crew into an apprenticeship, and keep proof of your hours: some apprenticeship committees only credit documented line construction work that includes climbing.