So right from the starting, very neat line work. The lines didn't converge a lot, but that gradually improved. Also, a tip for accuracy, draw the inner corner after drawing the Y (the bottom surface of the box). Try thinking of four parallel lines instead of just two. I don't have a problem with much else, your boxes are solid, which is the aim. Hope you see boxes in your dreams!

To add to what lemons said, by the end of the challenge (last 100 boxes or so) you end up focusing on extreme perspective a lot. Keep in mind that most of the boxes of the challenge should be done in shallow perspective as it's more common, so I would have liked to see some of those by the end of it, try to focus on them on your next warmups.

As for the convergences, extend them all the way through, don't worry about them colliding with other boxes. Doing this will make it a lot easier to localize your mistakes, example.

Boxes are pretty varied in general, so great in that regard, I recommend you to do some really big boxes though (1 box or 2 boxes per page), as you haven't done them on the challenge.

Your convergences are pretty good by the end of it, but take a look at this just in case you haven't seen it yet, it's basically about what lemon said of thinking about 4 parallel lines instead of just 2, but explained more thoroughly.

In general pretty solid job! You've improved a great deal over the challenge and the boxes end up pretty good in general so I recommend getting started on the advanced boxes exercises already, good luck on lesson 2 and keep it up!