The first Iron Man comic was 'Tales of Suspense #39'. This comic laid the foundation for Iron Man's popularity and his subsequent appearances in various comic series and story arcs.
The movie Iron Man 1 takes inspiration from various Iron Man comic storylines within the Marvel universe. It combines elements from multiple issues to create a compelling cinematic narrative.
Sure, Iron Man has retired in comics. It might be because he's exhausted, wants to focus on other aspects of his life, or there's a major event that prompts his decision. But comic storylines are dynamic, and he can always return when needed.