To answer your question; that is exactly what you will learn about and practice in the 250 Box Challenge.

Another quick note before I begin your critique, in the future, when you go to scan your homework submissions, it would be better to scan your homework using the "photo" setting instead of the "drawing" setting. The drawing setting tends to up the contrast on an image and can cause you to lose some of the subtlety in your line work.

Now for your critique, in your super-imposed lines you do a pretty good job of making your lines smooth and confident looking. Your ghosted lines also look pretty good with very little wobbling or arcing in your lines. The same applies to your planes homework where you did a goo job constructing your planes out of straight, smooth and confident looking lines.

For your ellipses you do a pretty good job of drawing through your ellipses which makes them appear confident and evenly shaped. I can see in some areas that you have trouble ending your ellipses cleanly. So, one thing you can do is when you want to end your mark try lifting the pen off of the page rather than stopping your arm. You did a pretty good job with your ellipses in planes. Overall your ellipses in this exercise have a fairly round and confident looking shape to them. The same can be said about your funnels which overall look good. I do see that some of them are slightly tilted along their minor axis. If you ever notice your ellipses are tilting, rotate the page until they line up correctly.

In your rough perspective boxes I can see you were careful when placing your boxes. You did a good job of keeping your horizontal lines parallel with the horizon and your vertical lines stay largely perpendicular. I do notice that your mark making quality dips a little here though. Keep in mind as you progress through Drawabox and begin to construct more complex forms that it is important to put in the time and focus required to execute each line correctly and to apply the ghosting method to every step of the process, as explained here. You should also frequently refer back to the instructions to ensure you are doing everything correctly and to the best of your current ability.

The rotated boxes exercise is a challenging and complex exercise and I think you did very well for your first attempt. Your boxes look well constructed with clean, confident looking lines. You also managed to get a good amount of rotation along the major axes. Your gaps are not very consistent which has lead to some of your boxes sticking out more. This is a common mistake and you can see another example of what I am talking about here.

Finally we have your organic perspective boxes. You have a good start here. You did well getting your sets of parallel lines to converge somewhat consistently towards their shared vanishing point. This, like I said before, is something you will work on more in the next steps. There are some areas where your quality dips again so keep in mind what I said above about taking your time as you continue through Drawabox.