Being fairly new also (4 months in) I would say that what matters the most is customer satisfaction at first. The customer isn’t going to want to talk about how much each window cost. They simply want your total price, and for you to do a great job with a great attitude. I wouldn’t recommend doing a 1 hour job on 20 windows. I would take your time to get it right, and inside out with sills and screens will take you 3 hours. I recommend driving out there to quote the first 5 homes because my experience was running into hard water, bushes completely covering windows (no room to walk in between), and people counting triple french panes as “1 window” over the phone.
Don’t be the cheap guy who acts desperate to land a job. Be the guy who quotes high, under promises, and over delivers. Then mail out thank you cards and remind people to leave you a review.