New USer of Mule ?

I have had emacs 21.1.2 for HP Unix installed.   I can't seem to get the
emacs to switch to the a different language.  I keep getting mini buffer not
active on the bottom when I go to the Option menu and set the language
environment.     I have a need to view Katakana and Kanji  Double -byte and
Single byte characters.   Do I have to set my language environment before I
start emacs.   Can I open file and switch from one language to another?  Do
I have to have any of the LANG environment variables set before going into
emacs?  Any help would be greatly appreciated.
 
Don.
 
Don Eytel
Nike Inc.,
Lead Integration Engineer