Look for something called a 'terminal'. Greet it nice and politely as you are going to be seeing quite a bit of each other
. If you can't see that then common ones are xterm, aterm, konsole, gnome-terminal, look for these in menus etc.
Whatever one you have it's basics are the same, a command line and a prompt (maybe user@system
This is where you will type commands, it's VERY powerful, and you will learn to love it and put that harlet of a GUI in the background.
the chmod command above is used to set permissions on files and directories, saying who can read/write/execute the files. the ins and outs of chmod are far bigger than the scope of thread, but a good place to start is type in the terminal
- this opens the manual/info pages for it giving you information on the program (q to quit), that method can be used for alot of programs so you can read what they are for etc.
Because changing permissions can lead to all sorts of problems it is only allowed to be done by the root user, that account is the god of your system, you can do anything with it. You should have set up a root password when you installed. To login as root in a terminal type:
insert yoru password and the prompt should change indicating that the user has.
It is then that you type the command as mentioned above.
I tried to give you the answers you needed but also the background info for you to diagnose similar problems yourself, sorry if it's confusing, stick with it, you won't regret it