Call me an elitist, but this reads like “I’m 10% fluent in a language but want to write a complex, multilayered novel in that language”. Reading music fluently (that means at least treble/bass clefs and probably alto/tenor as well) is probably the bare minimum you should have for something like that, and that’s if you don’t care if the parts are actually playable/readable by humans.

Grab a few orchestral scores off of IMSLP and study them and see how they’re put together - stuff like Beethoven’s 5th symphony, as overplayed as it might be, is perfect for learning how orchestration works, which instruments can do what and how they sound in different combinations, and the “grammar” of how music is notated correctly.