I run gitea in a docker container, and i found that there is no templates folder, and no public folder.
Tried creating them and restarting the container, nothing from the folder worked.
How can i fix this? Or how can i modify the website in some other way?
Make sure you are creating them in the custom directory. Go to Site Administration (in web browser) → Configuration → look for Custom File Root Path:
In my case, I would create
/var/local/gitea/custom/public (docs: Customizing Gitea | Gitea Documentation).