Babies and airplanes

I will be traveling in April by plane for the first time with my LO. He will be five months at the time and we are going to IL. I'm really nervous about flying with him, but if we want to visit family and go on vacations we have to start somewhere. Anyone have advice as to how I can make the plane ride as smooth as possible for my baby? He does get a bit fussy when he's in one spot for too long, but he's not a huge cryer. I just need some good advice on things to take, not to take, how to keep him entertain if he gets cranky, family friendly airlines, car seats on planes, etc😊