extract State Entity from String using regex_substr
You could create a table with a list of state names, and use that to cross reference against the list.

Something like:

SELECT s.state_name
FROM states s
    INNER JOIN addresses a ON a.address LIKE '% ' || s.state_name || ' %';


Since you cannot create tables, you could use a CTE with defined values for each state name, something like:

WITH states (state_name) AS
(
    SELECT 'Alabama' FROM dual
    UNION ALL SELECT 'Georgia' FROM dual
    UNION ALL SELECT 'Alaska' FROM dual
    ...    
)
SELECT s.state_name
FROM states s
    INNER JOIN addresses a ON a.address LIKE '% ' || s.state_name || ' %';


I'm not an Oracle rockstar; who knew || was concatenation