You can store it in an airtight container for 3-4 days. Of course you can fill the dough with whatever you like I'd just recommend not to go gaga with too moist ingredients. Or you will always have a sodden core. Don't use too many fresh tomatoes or too much mozzarella. Olives would be a nice add in as well.
And I've come to realize than many people are afraid to use yeast. Don't be! There are only two rules: Keep it warm but not too warm (50°C at the highest until you bake it) and treat in kindly - aka careful but vigorously kneading is a must. You can all do this! I promise!