Nice work here!

You understand your vanishing points and the relationships between your lines, your lines are confident and straight, and you drew your boxes at a variety of angles and perspectives.

There are a few concerns I have with the the pages. I notice that on your pages, you have a lot of dots all over the page. It is okay to use dots in order to help you visualize the positions of the lines and to plot your vanishing point. The problem is it makes the page messy and you won't be able to rely on that when you are doing actual drawings in perspective. In the future, instead of making a mark on the page for the vanishing point, use something else to help you mark it, like placing a finger there or the back of your pen with no ink, or just do without it and keep the position in your mind. You also won't be able to rely on this in situations where the vanishing point is completely off the page. It is not a big issue though.

The other thing is some of your thickened outlines look a little bit scratchy. In order to thicken lines, you should only go over twice with your pen, using the ghosting method and drawing confidently like you would with any other lines. Drawing small segments of line to fill it in makes it look scratchy, wobbly and messy.

These criticisms are nitpicky though, you did a great job on this submission!