Perspective is truly the artist's first true hill. Regardless you did quite well! your practice is quite organized and cool to see because we artists don't make a habit out of practicing too much so I love seeing you doing what will make you better. Good luck! the main thing I would direct your attention to is Vanishing Points. Basically if all these boxes were cars and you told the all the drivers to just go straight, you'll see them get smaller and smaller and smaller and closer to the red horizon line .At some point, they will vanish at exactly the same point. (something to note, this only works if the cars are facing the same direction) So. When drawing boxes that are all facing the same direction , the same happens. they will disappear in the same vanishing point which gives us the phenomenon of the lines of the box meeting at that point. In the boxes you drew below you'll notice the lines don't meet at a point which is why you felt it was "off" but at the top I drew boxes that do and youll see the green lines follow the box into the vanishing point I set for them. I hope that helped and have fun drawing!

