Hello and welcome to the forums.
Unfortunately, that's not the way we work here. You can post your writing and ask that someone take a look, but you need to be aware of two things: First, what you post will be searchable and we won't delete it afterwards to preclude those search results, and second, the longer the writing, the less likely someone will review it.
We also aren't keen on reviewing homework before it's submitted, as this gives an unfair advantage and doesn't show the teacher what you can really do (and therefore the teacher can't really help you improve).
However, once you turn something in and get corrections and you don't understand why those comments were made, we are very happy to help you understand them.