Short answers, pulled from the story.
John Lennon and Paul McCartney began composing She Loves You on the 26th of June 1963 after a concert at the Majestic Ballroom in Newcastle upon Tyne. They finished the composition the following day at McCartney's family home on Forthlin Road in Liverpool.
As of November 2022, sales totaled 1.93 million copies making it the ninth best-selling single of all time in the UK. The song became the Beatles' all-time best-selling single in the UK and held the position of best-selling single of any artist for 14 years until surpassed by Wings Mull of Kintyre.
She Loves You was released as a single in the US on the 16th of September 1963 under Swan Records licensing. It entered the Billboard chart on the 25th of January 1964 after appearing on CBS Evening News coinciding with its climb up Canadian charts.
The Beatles recorded She Loves You on the 1st of July 1963 at EMI Studios using a two-track recording machine. Producer George Martin initially called the final chord corny but the band insisted it sounded great while engineer Norman Smith admitted his initial reaction to the lyrics was shock.
The phrase yeah yeah yeah became synonymous not just with the Beatles but with popular music overall and parts of Europe even referred to them as yeah-yeahs or yé-yés. The BBC broadcast saw some quarters hailing collapse of civilized society while Communist German Democratic Republic General Secretary Walter Ulbricht referenced the song in 1965 speech saying yes we should put an end to monotony of yeah yeah yeah.