I've lived at least 3 lives as a writer, and I describe my various schedules and goal-setting procedures in each of them, including in my life now where I have a full time 9-5 job to work around, as well as evening and weekend work as a writing
Why you should stop obsessing about the first page before you've done about 10 drafts. You're only going to know what the right first page is when all the other pieces are in place.
One of the biggest things new writers forget to do is add emotional reaction for their character each time something happens. Without this, the reader won't have their own emotional reaction.
How do you run a marathon? 100 steps at a time. How do you write a book? 100 words at a time. Small goals make your brain shut up about how impossible and scary it is.