PSQL is its own world. Interacting with it simple, yet the language has to be learned. Here is a list of basic commands which are a must.
Launching PSQL on any terminal:
Create New User (users are roles with rights):
CREATE USER name;
Set a password for the user:
List all roles (users):
Listing all databases:
Selecting and working on a database:
Creating a database:
CREATE DATABASE name;
Note: The semi-colon at the end is mandatory.
Quitting PSQL (or some command screen):
DROP DATABASE name;