when did he start his career?
1956.
Willie Nelson
He made his first record in 1956, "No Place for Me", that included Leon Payne's "Lumberjack" on the B-side. 
i'll never smoke weed with willie again wiki UNANSWERABLE who is willie nelson? He is an American musician, actor, and activist.
wiki:1213669
Willie Nelson [SEP] Beginnings (1956–1971)
Nelson was hired by KVAN in Vancouver, Washington and appeared frequently on a television show. He made his first record in 1956, "No Place for Me", that included Leon Payne's "Lumberjack" on the B-side. The recording failed. Nelson continued working as a radio announcer and singing in Vancouver clubs. He made several appearances in a Colorado nightclub, later moving to Springfield, Missouri. After failing to land a spot on the "Ozark Jubilee", he started to work as a dishwasher. Unhappy with his job, he moved back to Texas. After a short time in Waco, he settled in Fort Worth, and quit the music business for a year.