For a group of families to transition to a local government is going to be difficult, IMO. They are going to have survived that first year by banding together and keeping outsiders away, but eventually, they are going to have to resort to inbreeding if they can’t get new blood into the community. So growth will happen.
My suggestion would be for the families that survived to take account of all the land they control and then inventory the lands between and around their properties. I would make this “common” land that is owned by the community as a whole. If the government needs money, they can sell some of this land or rent it out to be farmed, etc.
People tend to specialize. If one family has dairy goats and the next has wheat, then they can trade and both will have milk and bread. So one thing a community government will need to do is facilitate safe, free trade. Perhaps the local government can charge a 10% sales tax on all transactions in order to pay for security at the trade market.
Families and individuals that wander into the community that have skills or willingness to work, might be offered a deal by the local government to farm or ply a trade for a given amount of time, where they buy their land/home/workshop through their labor for a few years then own it outright.
I am definitely against a local government taxing private property, that is simply theft. So no income tax, no property tax, etc. I can see paying for services, like setting up a table at a swap meet, but the government should be small and stick to security of the community as far as I am concerned.