ooh! We have this all the time, luckily for fanfic specifically there is a great solution.

You take the one scene, or couple of scenes, in your idea that’s the most intense and interesting, and you make a one shot out of it!

damn the context! you don’t need to do the whole novel, you just need to get that one scene on the page.

Luckily in fandom, people really love that kind of thing.

As for plots you could not convey with your skill level– that is your brain lying to you. You can write any plot you can thing of. 💖

The worst thing that happens if you try to write a plot “above your skill level” is you go back and re-write it even better later.

There is no such thing as too good for you to write right now.