Does someone here know how to do this in clip studio paint?

Attached are my attempts at level 2. I did the assignment digitally this time - I had to try each pose multiple times and it was easier to erase this way. I think I got them roughly correct. In number 2 I am not sure if we see the bottom plane. I also think something is wrong with number 10, but I am not sure how to adjust it.

Here are some of my attempts. At the end I have decided to see if I can do a human, but I still need more practice before it will look good.

Below are some of my more recent attempts. Not sure if the portraits are boxy enough.

Hello, Here are my attempts at heads 1-3 (I plan to do the rest over the week). I had some trouble deciding where the top of the box should be - should it follow the forehead ond leave the top poking out, or go up to the top and leave a lot ampty space inside? I also couldn't decide in picture 3 if I was seeing the bottom plane or not.

This was hard but fun. Struggled a lot with 6, 8 and 9. I was drawing lines parallel to the 'eyebrow line' and the 'lip line' to find the box edges.

Hi everyone ! After few attempts on paper, it felt so difficult I chose trying tracing over pictures first. Even like this it was quite a challenge. I did all the picture this way but posted only a few. As the picture number grew, I felt a little more confident. Please let me know if it feels right to you. On most picture, it was really difficult to find convergence between the lines because I was really influenced by parts on the face. When I switched my mind into “cross contour” mode, it helped in my opinion. Waiting for your opinion on these and I’ll try again on paper without pictures underneath ! Thank you guys for your help !

My 2nd try, this time I have done it with a fineliner. Sadly, when going over pencil lines, I got confused what was in fron of what. I did some light cross hatching to try to take atention away from these mistakes. The lines are too wobbly. I get too focused on perspective that I slow down my strokes too much. I think the windowsill has the worst perspective errors here.

Does this count for lvl 2? I'll upload some more as the week goes on. I'm slowly warming up to this exercise. But I have to say, making stuff scale is so hard without reference. I'm aware that some of the chairs don't follow consistency as the ones closer to the viewer should always be bigger but by the time I'd notice I decided to just leave them be as I don't know how to properly scale them anyway. Heck the bust was one of the last things I included and that thing's way too big. By the time I drew it I was already aware that my objects weren't consistent in their size. The weird round thing is a poof and the robot man is inspired by Steven Zapata's Box Men exercise in his Beginner exercises course (check it out). This is inspired by my art classroom. Coming up with stuff to fill the room is taxing, not to mention with remembering how stuff that's there in the first place even looks. I refuse to use a ruler to help, am I being stupid? I know it's a tool and it's meant to be used but since I'm still learning it's better for my growth to try and ghost or do stuff by eye right? I can make it easy for myself and use these tools once I'm better is how I see it but do tell me if I'm being silly.

Here is my 1st attempt. For lines far away from the vanishing point, I had some problem getting them t point to the right direction. I also had problem keeping the longesst lines straight. I'll try to make a better one tomorrow.