At first when you spawn you enter the hub of many worlds, at the hub you have 3 portals. And there is Spleef and Mob Arena in the hub.
One of the portals goes to Kit pvp where you can chose a kit and pvp with other players and hot-soup. If you donate you get special abilities with this world.
People there work in a jail and cooperate with the guards. You work in the jail to gain money and work your way up to a free citizen. If you don't cooperate you get put in jail for some time.
This option is available in the 'Team' world and the 'Faction' world. There is a chance you can get a custom enchant when enchanting at level 30 in an enchantment table.
This world is called "Faction" there you run out of spawn and build a base. With the items that you mine or get you can pvp with other people. If you donate you also get many special abilities in this world. This world also get custom enchantments. This is like the team world except it has the faction plugin.