I’m specifically looking for sites where I can read manga, light novels, and books.
This is a site where you can read short stories made by people.
This site requires you to make an account, I just signed in with google. It lets you buy and read virtual mangas
This site allows you to watch japanese cartoons in japanese with japanese subtitles that function with yomichan.
If you get the light novels in epub format somehow, you can use the ttsu.app reader
It can also work off-line
Do I have to make an account under the Japanese language for it to be Japanese, or can I change it when reading?
manga is harder but you can use this kha-white/mokuro: Read Japanese manga inside browser with selectable text. (github.com)
The account works for both english and japanese
but it will sometimes default to the english section and you have to change over