Postico download: (Mac-specific, but there are other GUIs for Windows) https://eggerapps.at/postico/
Setup instructions: https://eggerapps.at/postico/docs/v1.1.1/
Chinook db script: https://raw.githubusercontent.com/xivSolutions/ChinookDb_Pg_Modified/master/chinook_pg_serial_pk_proper_naming.sql
After downloading Postgresql you will have access to the command line tool.
Open the terminal.
Type psql to enter the postgresql command line tool.
Type create database <db_name>; to create a new database that will be loaded from each data file (restaurant_db.sql and transact.txt)
For example
create database restaurant_db;
create database transactions;
Now exit the Postgres command line tool by typing \quit
To add the "dump" files to your empty databases use the following commands
psql restaurant_db < restaurant_db.sql
psql transactions < transact.txt
You should see a list of commmands flash over the terminal. This means that the data was added.
Now try to do a simple select statement to access your data
psql transactions
Now you've entered the psql commmand line tool and should see a prompt starting with "transactions=#"
Type select * from customers; You should see the contents of this table printed to the terminal. Now you're ready to start querying!
**And remember, control+C does not work to exit the psql command line tool in the terminal, you must type \quit or close the terminal window.