Need Help with Interview questions preparation for parents B1/B2 visa

Am originally from Mumbai India, currently employed in Indonesia, i am planning to take my family for vacation to USA in December 2023

Filled in DS-160 and can see available date to schedule interview through old USTRAVELDOCS

:one: Please hello to share you experience what interview questions to expect
:two: i do not carry my expired passports, and do not carry my original educational certificates. will that be of any concern
:three: what other documents copy do you suggest i carry for the interview