Well I think I've "enjoyed" 3 major earthquakes. Loma Prieta in 89, Northridge in the 90's, and Olive View in the 60's.
The first thing you need is a list you can grab with the location of everything important. Put on it shutoff locations, flashlights, water, food, jackets, spare clothes ropes and first aid. Include some money.
Having said that, the one (only) thing that was necessary was the flashlight. Electricity, water and gas will go out. Landline phone will stay up. Cell you should stick to texting - voice calls use too much bandwidth. If the earthquake is in the night or early morning (2 out of 3) then a flashlight is needed to scope out issues. Rarely are utilities out for more than a day or two. BTW, you don't need a shovel for a cat hole. Just some gallons of water to manually flush the toilet - perhaps a gardening barrel of non-potable water.