There are definitely a number of different ways to attack the editing process.
We recommend looking at dialogue first, as that’s one of the most critical sections of your writing. Is your dialogue really speaking to your audience? Are you using dialogue tags properly? What about adverbs in dialogue?
As a third step, you can use the Overused Words (under Compare to Fiction tab) to figure out where you have gone “way over” the limit vs. areas that are more within range. Once you have it narrowed down, each of these sections are detailed out in the Strong Writing and Word Choice sections where you can just focus on one at a time. For example, if you found in the Overused Words that you used way too many generic descriptions, you may want to switch to Word Choice –> Generic Descriptions to actually do your editing.
After attacking these sections, you could then run the Pacing reports to look at sentence variation and slow paced paragraphs. (Of course, this may be one you could start with in the very beginning of the process, too!)