To move all the tables from wherever they are now to one tablespace:

spool move_schema.sql

select 'alter table '||table_name||
' move tablespace users;'
from user_tables;


SQL> conn scott/tiger
Connected.
SQL> /

'ALTERTABLE'||TABLE_NAME||'MOVETABLESPACEUSERS;'
-------------------------------------------------
alter table BONUS move tablespace users;
alter table DEPT move tablespace users;
alter table EMP move tablespace users;
alter table SALGRADE move tablespace users;

spool off

Edit the spool file, save it, run it.