Step 1: Food
You need food more than anything. It's extremely critical to survival. Canned food with pull open tops are best since you don't need a can opener. Try to have a variety. You still need to stay healthy.
Step 2: Weapons
You may think it depends on the situation, but it doesn't. If you need to pull your bag out, there's a reason. In any catastrophic situation you will need to defend yourself, your family, and stuff you own. Even if you only have to for intimidation purposes.
Step 3: Water
Water is another vital resource. CLEAN WATER. You will obviously need to drink it. And you can't drink dirty water. Water may also be needed to treat and clean wounds.
Step 4: Medical Kits
Medical kits are extremely important. If you trip and get a cut, if you get attacked, if you have a misfire, if you get sick, if you break a bone. There are a thousand different reasons.
Step 5: Signal
If you are in a quarantined area or are trapped somewhere this is important. Strap some lights to something an make it fly. No matter what it is. Even if its just baking soda and vinegar.
Step 6: Survival Rap
The type I have here is a 52" x 84" foil wrap. This helps prevent heat loss, protects from sunburns, and can also be used as a signal. This is recommended, but you could just use a normal blanket for warmth
Step 7: Bug Spray
Bug spray I helpful, but not required. It can be good for the reasons of preventing bug bites. Mosquitos especially, west Nile can ruin any chances you have if survival. Along with other poisonous bugs. This is helpful
Step 8: Cleansing Wipes
Hygiene is surprisingly a huge part of survival. although dirt can be good camouflage, it can be fatal in some cases, along with other dirty things. Such as feces, blood, and once again, insects. Dead insects can leave busted poison sacs on you. Get them off immediately. Dirt and feces are known to carry various diseases.
Step 9: Multi-Tools
Obviously, multi-tools are very, very helpful. Containing knives. Files, scissors, and tweezers. All of these things have various uses. Which are all obvious once again.
Step 10: Your Bag
You need a bag to carry all of this, duh. Try to get a high capacity bag with lots of pockets. Tactical vests are good too