Definitely not. Justice League is a creation of DC Comics. Marvel Comics has its own set of superhero teams and characters that are distinct from those in the Justice League.
The Justice League typically includes well-known heroes like Superman, Batman, Wonder Woman, The Flash, Green Lantern, Aquaman, and others. These characters form the core team.
The 2017 Justice League movie isn't from Marvel Comics. It's part of the DC Comics franchise. DC has its own unique set of heroes and storylines that are distinct from those of Marvel Comics.
It's hard to give an exact number because new comics are constantly being released. But there are definitely hundreds of Justice League comic issues over the years.
Definitely not. Justice League is a property of DC Comics. DC and Marvel are two separate comic book universes with their own distinct characters and storylines.