This website has thousands of books, magazines, music, and the Wayback machine to view old webpages. It has SO many things! check it out sometime.
Gifcities
Gificities is a website from Internet Archive, you can search for gifs saved from geocities websites.
Glitter Graphics
This is another website where I find a lot of 2000s graphics, dividers, backgrounds and more.
Library Genesis
The best website for finding free books online!
Calibre Ebook Reader
App that lets you read .epub files from LibGen. Also entirely free.
W3 Schools
a great website for learning HTML and CSS, and its completely free. It was a huge help for me when I was first learning, and I still use it now.