I've struggled with this same question as the typical advice is go slow, don't get ahead of yourself, and don't make bad habits.

However, my experience has been I move on when I'm ok or even moderatley poor at a lesson before moving on. I'm probably 80% of the way there at best. BUT I frequently backtrack and redo some of those lessons later. This keeps it fun or else I would have been stuck for 6 months trying to strum a "perfect" F barre chord.