SQL Query to get dates of X days after current date

You may use generate_series.

SELECT generate_series(current_date + 1, 
                       current_date + 2, 
                       interval '1' day)

Docs

In plsql, you may set x as variable and then use it in your query.

knayak=# \set x 5
knayak=# SELECT generate_series(current_date + 1,                                                                                                            
                                current_date + :x,                                                                                                                        
                                interval '1' day);

 generate_series      
---------------------------
 2018-05-19 00:00:00+05:30
 2018-05-20 00:00:00+05:30
 2018-05-21 00:00:00+05:30
 2018-05-22 00:00:00+05:30
 2018-05-23 00:00:00+05:30

You may format the dates in desired format with TO_CHAR

SELECT  to_char(dt,'DD-MON-YYYY') as dates
FROM    generate_series(current_date + 1, 
                        current_date + 2, 
                        interval '1' day) as dt

dates    
-------------
19-MAY-2018
20-MAY-2018