How to configure postgresql for the first time?

Question

I have just installed postgresql and I specified password x during installation. When I try to do createdb and specify any password I get the message:

Answer 1

In MacOS, I followed the below steps to make it work.

For the first time, after installation, get the username of the system.

$ cd ~
$ pwd
/Users/someuser
$ psql -d postgres -U someuser

Now that you have logged into the system, and you can create the DB.

postgres=# create database mydb;
CREATE DATABASE
postgres=# create user myuser with encrypted password 'pass123';
CREATE ROLE
postgres=# grant all privileges on database mydb to myuser;
GRANT