These are the steps I normally follow when restoring Oracle dump files for the purposes of my work.
I prefer to logically keep the restored entities logically and physically separate through the use of tablespace and associated datafile(s) respectively.
CREATE BIGFILE TABLESPACE xxxTBS DATAFILE 'xxx.DBF' SIZE 1000M AUTOEXTEND ON
Create and assign the user to the earlier defined tablespace.
CREATE USER xxx IDENTIFIED BY password DEFAULT TABLESPACE xxxTBS QUOTA UNLIMITED ON xxxTBS
If I want the created user to log in to the database, the statement below is executed.
GRANT CREATE SESSION TO xxx
And now to the import part,
IMP system/[password here] IGNORE=Y FROMUSER={...} TOUSER=xxx FILE=path_to/file.dmp;
In the sample above, the FROMUSER will be SA