Getting Started newbie questions)

I'm new to both Linux and Postgres

I installed Red Hat 8 on a stand-alone test machine yesterday. I did a
custom install, and installed everything. So my assumption is that
everything Red Hat 8 could install was installed, including Postgresql.

I went into Server Settings, Services, and in Service Configuration found
postgresql. I checked it, so that it would start on reboot. The machine has
since been rebooted

The tutorial says the Postgresql is stored in /usr/local/pgsql/ and
/usr/local/pgsql/data. I don't see either one, either as me (Steve) or as
root. I do see files under /usr/lib/, usr/share/, and usr/include.

The tutorial says to try to create a new database with

$ createdb mydb

I get the error:

psql: FATAL 1: user "Steve" does not exist
createdb: database creation failed.

This sounds to me like postmaster is running. But what do I know?

The tutorial says to try the command with the absolute path:

/usr/local/pgsql/bin/createdb mydb

I get the error:

No such file or directory

No surprise there. I already saw that I couldn't find a /usr/local/pgsql

Steve