Congratulations on finishing the box challenge! You've done a very good work overall, and have improved a lot over it, your line confidence and execution is pretty good in general, but there are some issues and things I want to point out so you can keep improving:

-You tend not to extend the line extensions extensions much, probably because you're afraid they would collide with other boxes, but don't worry about this. Extend the lines all the way through even if they touch other boxes, it will help to figure out better where your mistakes are.

-I think you're struggling sometimes to get different orientations and types of boxes, so don't forget that you can extend boxes in any direction, and check this diagram to see if it gives you more ideas on what types of boxes to create.

-Your convergences improved a lot since the beginning when you started having divergences on the outer lines and by the end of it the only thing that really gives you trouble is the inner corner. This is pretty normal, most students still struggle with it after finishing it, and this issue will get fixed with time, as it's the result of the accumulation of all your previous mistakes on the guesses, but there are a few things that might help you to get it better sooner:

+Try this order of drawing boxes, it helped me to get the convergences of the inner corner instantly, and has helped many others, so make sure to give it a shot.

+And the second thing is to take a look at this diagram which is the reason why the order of drawing above helps. By thinking more about the relationships between lines on boxes, you'll be able to make more accurate guesses on each step you take, which will result on getting overall better convergences, including the inner corner.

Overall like I said you've done great progress on it, and I recommend going on with the advanced exercises as soon as you get more comfortable with the inner corner thingy I mentioned. Congrats once again and good luck in lesson 2!