I feel like I have a half decent understanding of CSS and how to implement it. But to entirely write from scratch is a whole other ballgame. Some of the CSS on some of the projects I definitely could not figure out without heavily referencing css-tricks.com and moz docs and a working version of it side by side.
It’s an assigned project, so it isn’t expected to display a ton of creativity. Choose your own subject matter for the project, but it’s fine if the layout looks more or less the same. Do not copy code. If you find yourself looking up how to do something with code, that’s fine but you shouldn’t really be copying it. Look at it, figure out how it works, close the window, take a walk or eat a snack or something, and then come back and write your own code without referencing someone else’s solution.