默认情况下,根目录文件和文件夹是否被锁定?

I just installed elementary OS dual booted with windows 10. After the installation. I saw that the / root directory has every file and folder locked. I can't rename, delete or create anything there. Home directory is fine. I ran

sudo chown -R $USER: /

command from internet to get permissions and all folders were unlocked. But now after reboot I can't login. It just doesn't show the login screen. It shows a black screen with blinking _.

我想问以下问题-

  • Are the root directory folders locked by default? If they are, do I need to unlock them for some reason in future for installing some software or any other reason? If I need them unlocked for some purposes, how should I do it correctly?
  • I pressed Ctrl+Alt+F1 on black screen and I can login as my username. But couldn't do much. Can I reverse the process to login again? If yes how?

我是linux的新手。我不知道当我是唯一的用户时,为什么拥有root权限。如果root拥有权限,那么我只是使用操作系统的人之一,那么该怎么办只有root拥有权限的事情呢?