I am also a contracted writer and I can say that you need to at least have 50k words to apply for a contract. You can simply fill the form to apply for a contract from the help center and submit it. No one knows the fixed criteria on which basis the contract is given.
I also filled that form and got a contract the very next day. It may also take a few days to get a reply from them. But you had to have a required word count and enough views. At the time I got contracted I had views less than a million but need to have at least a sufficient amount of viewership.
And they don't provide to editors to edit your chapters but they could suggest you few things to make your novel better and it depends on you to use their suggestions or not. They can help you to find a one if you want but you need to deal with the editor yourself and pay then.
Getting into a contract does not bind you in any way. It only encourages writers to write more sincerely and make our novel better. And what's better to get paid for the thing we have started for fun?
Idk about others but I completely started to write a novel for fun but becoming a contracted writer, encouraged me to write more sincerely. You should try to fill the form if you have at least 50k words. I hope you get contracted soon.