How do you guys go about editing

So I have like two chapters left of my first draft, and I have been thinking about editing. So I know you should wait a couple of weeks, structural, line by line and all that. But it all feels so overwhelming, like my grammar is kinda shitty and I don’t know like what to do. When du you know you are read, what to change or if it’s good. Especially since I used around 40 days to write it all, the editing feels so long and time consuming