We're going to Hungary in a few weeks. I'm bringing my sons car seat cause I know he'll atleast be good for majority of the time. When the plane takes off and lands give them juice so they're ears don't pop as bad. Have snacks and books. My son loves to color. Also I downloaded his favorite movies and tv shows on my phone that he can watch! Of course have their favorite blanket and maybe stuffed animal that they like! And a change of outfit with diapers in case of messes! Our flight will be about 12 hours with two planes! So I understand where your stress comes from. This will be my husband and sons first time on the plane! Good luck!

Snacks cup or bottle binky cartoons honestly I recommend getting him his own seat for that long of flight I did a flight from Chicago to lax and it was rough and toys