Here is a more complex sentence using those words: 'Mine is the boy for whom a novel is a great source of inspiration.' This shows how we can use the words in a more elaborate and meaningful way.
No. Reading manga is just a hobby. It doesn't mean you're a weeb. A weeb is typically characterized by an excessive and sometimes inappropriate infatuation with all aspects of Japanese culture, beyond just reading manga.
It's possible, but it requires a lot of dedication and a bit of luck. You need to build a strong fan base, get noticed by publishers, and constantly improve your art.