Hey! What part of Alabama are you from??? I'm an Alabamian born and raised
So, sorry I can't help you out with the food part.
As far as decorating your apt. I would not worry about it too much. Seriously, they should understand that you are young and young people usually don't have immaculate apartments, you know? And as far as everything else, I hope you aren't doing it alone and that Phil is helping you. This is HIS family, you know?? It should not be ALL on YOUR shoulders to entertain them and find places for all them to sleep. I DEFINATELY think it should be Phil's responsibility to buy air mattresses and such for HIS family. That is SO nice for you to cook for all of them...but cooking for that many people is expensive. You should not worry about spending MORE money decorating your apartment and buying air mattresses for HIS family. You are so much more kind than me.
I think you and Phil should set aside a couple of nights a week to sit down and get everything down on paper as to what you are going to cook, sleeping arrangements, entertainment, etc. Since it is HIS family, he should have a pretty good idea of what his family likes to eat, what they like to do, what their expectations are as far as sleeping arrangements, etc. Who knows....maybe his family isn't even expecting that much.
Considering your past situations with Phil, I think this would be an excellent opportunity to open up the lines of communication. Please DO NOT take all of this upon yourself. This is PHIL's family and he needs to be doing MOST of the work that will be involved with HIS family coming to visit. You have already volunteered to cook the whole Thanksgiving dinner. That is more than I would do!
Best of luck! Let us know what you decide and how it turns out!