The First Five Weeks Of Graphics Course

Hey there, one of the subjects I chose was DVC ( Design and Visual Communication ) hoping to improve my drawing skills. I learned how to correctly use instruments, rendering and using line techniques. There are 3 types of line that we use on DVC: construction line, final line, and an outline. I also learned how to choose colors that contrast to make my drawing look colorful. Here are my drawings that I have been working on for the past 5 weeks,

It was handy that we used the instruments because it was hard to make straight lines without a ruler. What can I do better next time? What did I do wrong? Please tell me in the comments