I am loging as root right now.

I like to search and find the file that contain the text of "NBC 10.5" Both string and number.

I know I need to use grep, but how do I use it???

Oh, yeah if I do, grep 'NBC' *
then it gives me error
grep: can't open usage

i thought root can open any files....

Check what is the "usage" file. What are its permissions?

The permission is rwxrwxrwx owner is root

When I do ls command, usage is show like usage@ it looks like it is shortcut/link file and broken link maybe???

It is a symbolic link, i.e. a file containing a name the link points to. That file might be deleted, but the link remains intact. Delete the link or move it to another directory and try again.

My system admin says that
"Unavoidable... that dir has sym links off to other machines .."

Crap!

He said I do this
find . -exec fgrep 'NBC 10.5' '{}' ';' -print

What does it mean???

It means start finding NBC 10.5 starting from the current directory and recursively looking through all files and directories and their files/directories until all files and folders are searched. Then return the results.