Command line is not hard to learn. Here are some quick tips:

Command --> Result
pwd --> Tells you your 'present working directory'.

ls --> Lists contents of current directory.

ls -a --> Lists everything in current directory, including hidden files.

cd SomeDirectory --> Goes from your current directory to a child directory named SomeDirectory (if it exists)

cd .. --> Goes from your current directory to the parent directory.

rm SomeFile --> Deletes the file named SomeFile.

rmdir SomeDirectory --> Deletes SomeDirectory.

mv something somethingnew --> moves or renames something to somethingnew.

cp something somethingnew --> copies something to somethingnew.

Those are most of the commands you will ever need to know to navigate the command line. Oh, and one more tip, when typing the name of file or directory you can use Ctrl + i to let the shell finish typing the name for you. Play with those commands a bit. It will pay in the long run.

Edit: OK one more. The * is a wild card. So in order to remove all the files in the directory named /somedir/somesubdir. You would do:

rm /somedir/somesubdir/*

or, if you are already in /somedir/somesubdir, then just do:

rm *

(Of course, always be sure that you are where you think you are.)