I was in the USN in the days of wooden ships and iron men!!!
Well, not quite, but it was a long time ago. We were trained in the electronics of the time: tubes and transistors. Navy electronics was an excellent background for the HVACR business. Was actually introduced to the refrigeration vapor cycle because it was required to cool our electronics gear and we would help the mechs troubleshoot. The mech shop CPO talked me through a "home project" and I was hooked. Out of the Navy and into HVACR.
Always going to school at night while working during the day.
Worked my way up in the trade, then into design, then project management. Always continuing technical, then engineering school at night.
A regular customer told me, many years ago, when I was discouraged with my progress: "hang in there, I know that you will eventually make it."
Many things are tougher for you younger guys: the economy, jobs, etc. It's really tough starting out now. (Especially if you have kids!)
But the advice was and is still good: Hang in there. Learn all you can on the job, show your appreciation by being on time and staying focused.