Feedback+advice with Web Dev101 Mini Project: Google Homepage

Hello, this is my first time coding in html/css and I actually spent quite a bit trying to figure out how classes, anchors etc are connected. I got a website front end look a like working, but I feel like I brute forced the code without any structure whatsoever. I would like some comments/advice on improving and understanding the code better!

Here is my website

Here is my code from github