A young musician discovers that the English language reveals a conspiracy, which he utilizes to make himself a star. He competes with other celebrities, vying for power over the fate of the world's largest fanbase.
I think this is stronger, but there's still an issue with the timing - if he discovers the conspiracy, then presumably it takes a while for him to become a star? In essence, where does the film start? Is he a star already or has he just discovered the conspiracy, or is he just about to discover it? All three of those are different stories, with different stakes.
The second part of the logline is better as we now see the antagonistic force (the other celebrities), but what are the stakes? I wasn't sure what 'fate of the world's largest fanbase' means - it sounds like the world's largest fanbase is threatened with death. Also, the stakes should belong to the protagonist, not the fanbase, or others. In what way does he compete with celebrities?