You need not create a listner for oracle, if oracle is installed on your system there will be a listner configures on your system.
It will be available in
controlpanel--->administrative tools---------->services
Actually listner is a service which is responsible for interaction between client and server.
This listenser service should be running .
and if u want to create a new user
log in to SYS or SYSTEM or any othere user account which has create user system previlege
then from that schema execute this
- CREATE USER USERNAME IDDENTIFIED BY PASSWORD;
it creates the user.
next grant certain previleges
- GRANT CONNECT,RESOURCE TO USERNAME;
Now this user can connect and create his objects.