I first started programming my Atari 400 in BASIC In late 1983 or early 1984 when I was 13 years old. I don’t think I did much programming on it because of the horrible keyboard. Later in 1984 we got an 800XL, which had a much better keyboard and one of the first “substantial” programs I wrote with it was called “Hi Card Wins!”, an overly long program that simply played the card game of War. I apparently wrote it in January and February 1985.
With this program I was trying out all kinds of BASIC commands and it was certainly a victim of scope creep as the printout is 3.5 pages!