The course does require you to do the lessons in a particular order, so there isn't really a way to avoid submitting lesson 1 and the box challenge. The material builds on itself, providing you a sizable but manageable chunk to digest.

Of note is that the recommendation to not tackle the next lesson/challenge in line before receiving feedback is to make sure you avoid mistakes that could be made and caught in the previous assignment. You can always submit the lesson 2 you've done when the time for it comes, but do take into consideration what I have written above.