There are a lot of things you have to think about when you're editing your work. There are a lot of rules and conventions that you have to remember. There are a lot of ways you could go wrong.
Here is one that I was recently reminded of when someone else read my work: Your reader doesn’t know what you're thinking. They don't know what's important and what's not. They don't know why someone is asking a question or why you aren't telling them something. They don't know that you know what you’re doing.
So, you have to show them. You have to edit your writing to make sure that you're showing your reader what they need to trust you. Tell them where you are. Tell them when you are. Tell them who these people are and why they matter. Tell them what each pronoun means.
When you're editing, don't just worry about grammar and spelling. Remember that your story has to make sense to someone who doesn't know where you're going. Make your story clear and then worry about the details.