Why am I getting table does not exist error?
The table isn't missing. The message "table "automobiles" does not exist, skipping" stems from the DROP TABLE IF EXISTS statement and just informs you that there wasn't such a table to be dropped. 

If you look at the message it starts with NOTICE: which tells you that it's not an error. Error messages start with ERROR: (as you can see later on in your script)

Your table was successfully created. 



However, your INSERTs are failing as you are providing the values for the date column in the wrong format. The most robust way to supply a date constant is to use the ANSI SQL syntax for dates: DATE '2018-03-12', so your inserts should look like this: 

INSERT INTO automobiles(id, make, model, year, owner, msrp, purchase_date) 
VALUES
(   1,
    'Ferarri',
    'F40',
    '1987',
    '',
    '1690000',
    DATE '2019-03-12'), 
(   2,
    'Tundra',
    '4X2',
    '2019',
    '',
    '39625',
    DATE '2019-03-12'), 
...;


If you don't like the ISO formatted date literals, you can also use the to_date() function instead: to_date('3/12/2019', 'mm/dd/yyyy').



The message 


date/time field value out of range: "3/12/2019"
LINE 8:  '3/12/2019');
         ^
HINT:  Perhaps you need a different "datestyle" setting.



suggests to change the DateStyle setting in order to allow the implicit conversion of a string value like '3/12/2019' to a proper date. 

I strongly discourage the use of the DateStyle parameter as that makes your SQL statements dependent on the environment and they might still fail when run on a different computer.