How to create a user in Oracle SQL Developer


I am newbie to oracle sql developer, and have just installed it on my machine. I want to make a new connection, but it requires a user and a password which I do not know. I have been googling about it since many days, and have learned that there are some commands to create user, but I do not know where should I run those commands, because I cannot run queries/commands until the connection is created. Would anyone let me know what should I do?

Steps for creating new user :

1)Open Sql Developer, make new connection.

2)Login with System username and password(made during installation).

3)Once you connect, Right click users and add new user.

4)Give its username and password & select appropriate system privilege.

5)You are done now, check by making new connection.