I am new to Linux, but If you are trying to change permissions on files or folders try using:
this will let you open nautilus as root.. Now, you can navigate to the files and change the permissions by right-clicking and selecting properties. Then, click the permissions tab.
BE CAREFUL WHEN USING root
If you get some wierd message, and have not created sudo.
I recommend removing Use 'ALL=(ALL) NOPASSWD:ALL' from the code:
echo 'loginname ALL=(ALL) ALL' >> /etc/sudoers
Where 'loginname' is your user account.
Use 'ALL=(ALL) NOPASSWD:ALL' if you don't want to be prompted a password.
If you are prompted for a password with 'sudo' it is the user password, not root.
This way you will have to enter a password for root access through sudo.
If you don't take out the code above, and someone got their hands on your system, they could really do some damage.