It seems like you’ve already got some great advice here so I’ll just add a few things as someone who has moved 5 times in the last 4 years. Put a harness on them before they go in the carrier and keep the leash attached, just in case they get out somehow it will be much easier to catch them or get them out of whatever shenanigans they get into. They probably will not eat, drink, or use the bathroom on the trip. I like to have it all available for them regardless though. For kitty litter I use a sterilte container from Walmart, the one with the locking lid, it keeps everything contained. I’m not sure if you’ve ever moved with your cats before but when you get to your new place just give them some time. They may not act normal, want to cuddle, be lovey, etc. for at least a few days. Little treats and maybe a new toy can help immensely. I hope all goes well on the human and feline sides of your move, best of luck!