@PhoenixVengence Honestly, I think you should write for you, not everyone else.
In terms of fanfiction, Eragon isn't actually that big of a fandom for writing - don't get me wrong, there are some gems out there. I love the 'luminescence' series with Mal as the MC.
The lore is a little sparse in some places, but that means you can get creative and really have fun with it. Add something cool and new - or something small that you think the OG story really needed.
But if you really want to write it and you're passionate about the story you're writing, it shows and I think that's more important than any plot, or any storyline tbh ☺️
Paolini started writing it as a kid, I think he was 15 when he started writing them. So it's okay if there's a few mistakes, as long as you love it, that's all that matters.
Ps. If you do start publishing it, feel free to drop a link. I love reading new fics, especially in a world as amazing as Alegaesia.