I was a temp at a plastic pipe factory. I answered the phones. All twelve lines often rang at once. The job was partway between home and Raritan Valley Community College where I was enrolled in night classes in photography and drawing. I was about 20.
I usually listened to classic rock radio while commuting eastbound and westbound on Routes 78 and 22. WMMR or WZZO. Back and forth, I adjusted the dial on my 1991 Ford Escort. Unlike the local college radio stations like WPRB which I listed to at home, the classic rock stations played and replayed the same songs again and again. The repetition of CCR, the Doors, and Led Zeppelin meant I could learn the lyrics and sing along.
That is how I learned to sing.