As someone who has been there, done that...
CONCEALED pistol. Do not show your firearms unless absolutely necessary.
Full mags, no loose ammo.
It will be hot, humid when you get back. No air conditioning, etc. So, plenty of OIL for your firearms. Cleaning gear, etc.
You will need your own drinking water. If you didn't bring it in, don't drink it unless you boil. If you can't boil, 6-7 drops of bleach per gallon of water will purify it. Let sit a few hours before drinking.
This is back to basics... you need a way to make FIRE. Kitchen matches, or a few fresh 9v batteries and some 0000 steel wool as a fire starter. The little trioxane tabs are good, have eaten more than a few meals over these.
Canned food. BRING A MECHANICAL CAN OPENER... duh! If canned, make sure it is stuff you can eat cold right from the can.
If it must have ice to remain good, leave it somewhere you can buy ice. Standing in line to buy ice is a waste of your time, you have more important things to do.
Bring your own food, MRE's are good, too.
Flashlights, I prefer Maglights. Bring extra batteries AND some spare bulbs.
Bring some tire repair kits (No, not one, half a dozen) and 12v air compresser, you may have to do this yourself. There will be shingles and nails in the road.
Pocket knife and big hunting knife, or kbar.
Do you have trees? possibly chainsaw. If so, bring gas and oil for chainsaw, extra chains, any tools needed to change.
Help your neighbors, but avoid police and national guardsmen. Those guys are overloaded, and will generally be acting like assholes. Just avoid them.
Anyone from the government who is there to help you, knock him on his ass and send him home. Tell him he is not wanted there, go away.
Stay indoors, or at least not visible from the street, at night.
Cell phones may or may not work, due to cell towers being down. Don't expect cell phones to work.
I have a cable kit and the software to hook my laptop to my cellphone, use it like a modem. It is very slow, about 19k, but will link up. And my provider charges extra for getting online, but it does work.
Street signs may be down. This makes it hard for outsiders (extra po-po's and other workers) to find anything. This can work to your advantage if they don't know where they are.
Don't allow anyone you don't know personally to approach you. Warn them away.