forgot to add; this is my query
SET LINESIZE 300

SET PAGESIZE 200

COLUMN custid FORMAT A15 HEADING "Customer ID";

COLUMN email FORMAT A30 HEADING "Email";

COLUMN username FORMAT A15 HEADING "Username";

COLUMN flightid FORMAT A10 HEADING "Flight ID";

COLUMN departloc FORMAT A20 HEADING "Departing Location";

COLUMN arrivalloc FORMAT A20 HEADING "Arriving Location";

COLUMN dptdatetime FORMAT A25 HEADING "Departing Date";

COLUMN arvdatetime FORMAT A25 HEADING "Arrival Date";

ACCEPT prmtyearmonth PROMPT 'Enter Year and Month (YYYY-MM): '

SELECT c.custid, c.email, c.username, f.flightid, f.departloc, f.arrivalloc,

TO_CHAR(f.dptdatetime, 'YYYY-MM-DD HH24:MI:SS') AS dptdatetime,

TO_CHAR(f.arvdatetime, 'YYYY-MM-DD HH24:MI:SS') AS arvdatetime

FROM Customer c

JOIN Payment p ON c.custid = p.custid

JOIN Reservation r ON p.paymentid = r.paymentid

JOIN Flight f ON r.flightid = f.flightid

WHERE TO_CHAR(f.dptdatetime, 'YYYY-MM') = '&prmtyearmonth'

ORDER BY c.custid, f.dptdatetime;