Database Software

Hi,
I have very less idea about the multiple language support in oracle database.

select * from nls_database_parameters where parameter like '%CHARACTERSET';

It returns me:
NLS_CHARACTERSET AL32UTF8
NLS_NCHAR_CHARACTERSET AL16UTF16

SELECT * FROM NLS_SESSION_PARAMETERS;

It returns me:

PARAMETER VALUE
NLS_LANGUAGE AMERICAN
NLS_TERRITORY AMERICA
NLS_CURRENCY $
NLS_ISO_CURRENCY AMERICA
NLS_NUMERIC_CHARACTERS .,
NLS_CALENDAR GREGORIAN
NLS_DATE_FORMAT DD-MON-RR
NLS_DATE_LANGUAGE AMERICAN
NLS_SORT BINARY
NLS_TIME_FORMAT HH.MI.SSXFF AM
NLS_TIMESTAMP_FORMAT DD-MON-RR HH.MI.SSXFF AM
NLS_TIME_TZ_FORMAT HH.MI.SSXFF AM TZR
NLS_TIMESTAMP_TZ_FORMAT DD-MON-RR HH.MI.SSXFF AM TZR
NLS_DUAL_CURRENCY $
NLS_COMP BINARY
NLS_LENGTH_SEMANTICS BYTE
NLS_NCHAR_CONV_EXCP FALSE

Can you tell me,according to the above configuration,what languages will be supported by this database(oracle 10g)?
I would need to store german,japanese,chinese and etc...Is it possible to do so?
Can the change in the database setting help me to achieve inserting as well as retrieving data in numerous languages?Then what is the change that needs to be made.I don't want any junk values like inverted question mark during retrieval.
Can anyone please help?
Thanks a lot in advance.