Short answers, pulled from the story.
The Avengers made their first appearance in The Avengers #1 with a cover date of September 1963. Stan Lee and Jack Kirby created the team to sell new books and cross-promote existing Marvel characters.
Iron Man, Thor, Ant-Man, the Wasp, and the Hulk formed the initial roster of the Avengers. Captain America joined later in issue #4 after being found frozen in ice.
Their headquarters was a New York City building called Avengers Mansion provided by Tony Stark. Edwin Jarvis served as the faithful butler who maintained the mansion's state-of-the-art technology.
The 1970s introduced the Kree-Skrull War spanning nine issues starting in The Avengers #89. Mantis joined the team along with the Swordsman during this era while the Celestial Madonna arc linked her origins to the conflict involving Kang the Conqueror.
The West Coast Avengers launched as a four-issue miniseries in 1984 before becoming a regular monthly book running 102 issues. This base sank during the Acts of Vengeance crossover event.
As of June 2022, the MCU grossed over $26 billion collectively making it history's highest-grossing franchise. Star Wars trailed significantly behind at less than half that amount.