+1 to Shalym's suggestion of gutenberg.org.
You might also look at OpenLibrary.org for books that can be "borrowed" for two weeks and can be read online (or downloaded). Limit of 5 books can be checked out at one time. They have a lot of books much newer than Gutenberg --- be sure when you search to checkmark to "show ebooks only" or it will pull up lists of library paper books as well. (OpenLibrary is affiliated with archive.org, the Internet Archive.) Free registration is required to access the books, but it is painless --- only asks for a valid email to send your account activation link.
Books at archive.org can be freely accessed. When you search out and click to select a title, a smallish window displays the book --- click the "Search Inside" magnifying glass beside the display to read in a larger window.
https://www.hathitrust.org/ has a LOT of books in pdf that can be read online. Free access, but I'm not sure if access is worldwide or not.
If short stories sound like a better deal, try
https://americanliterature.com/short-stories
But there are probably hundreds of sites out there offering "on-line" literature --- as a matter of fact, just google "read online" and be amazed at all the links that pop up.