[wellylug] How to start postgresql

[Colin & Josephine Lewis]

I am wanting to start to get to know Postgresql, but cannot figure out
the command to start a new postgres session and establish myself as a
valid user.  I know the Postgres server is starting when my machine
boots, but nothing appears in the Gnome menus to indicate its presence,
so figure I must drive it from a terminal.  I am running the latest
version of Debian if that helps.

Any assistance appreciated

Colin