Short answers, pulled from the story.
The 1946-47 BAA season was the inaugural season of the Basketball Association of America, a professional basketball league that launched with 11 teams playing a 60-game schedule. The season ended with the Philadelphia Warriors beating the Chicago Stags 4 games to 1 in the BAA Finals to become the first BAA champions. The NBA later recognized all three BAA seasons as part of its own official history.
Ossie Schectman of the New York Knicks scored the first basket in BAA history on the 1st of November, 1946, during a 68-66 Knicks victory over the Toronto Huskies at Maple Leaf Gardens in front of 7,090 spectators. Because the NBA recognizes the BAA seasons as its own history, Schectman's basket is also considered the first in NBA history.
The Philadelphia Warriors won the first BAA championship by defeating the Chicago Stags 4 games to 1 in the 1947 BAA Finals. Joe Fulks of the Warriors led the entire league in scoring that season with 1,389 total points.
Four teams folded before the BAA's second season: the Toronto Huskies, the Pittsburgh Ironmen, the Cleveland Rebels, and the Detroit Falcons. Toronto and Pittsburgh ceased operations immediately after the inaugural 1947 BAA draft concluded. Every original Western Division team had folded by 1950.
After its third season in 1948-49, the Basketball Association of America merged with the National Basketball League to form the National Basketball Association. The NBA recognizes the three BAA seasons as part of its own history, making the 1946-47 BAA season effectively the first NBA season.
Players fouled out after five fouls rather than the six used in the modern game. Zone defenses were initially permitted but banned entirely on the 11th of January, 1947. The league also briefly experimented with 60-minute games played in 15-minute quarters, beginning on the 11th of December, 1946, but abandoned the format after only three such games.