Things you can do now or this summer to help prepare you for any emergency, not just a zombie uprising:
Put fresh batteries in your flashlights and emergency radios.
Make sure that you have a shelter space in case of a storm.
Make sure that your shelter space has fresh water in it.
Start building up a one-year food stockpile for $5 a week
Create a Bug-Out Bag (or a Z-Kit, if you prefer).
Take a red Cross CPR or First Aid course.
Take a self-defense course.
Learn how to change a flat tire and add coolant to an overheating radiator.
Go on a diet and/or get in better shape.
Get a map of your county and learn where all the evacuation routes and emergency shelters are.
Now test yourself: Pretend you have 30 minutes to evacuate. See if you can pack enough clothes and supplies to sustain yourself for 3 days or more. Are you prepared for harsh weather (rain, cold, excessive heat)? How about your family? How about your pets?