Kalle801 The plugin is, by default, set to kovan. You would have had to update the base url in the config to switch to main-net. The plugin doesn't differentiate between enj/eth & kenj/keth. It just uses the main-net symbols across the board.
You do need to mint tokens, but you also have to send them to players somehow. We don't provide any sort of gameplay mechanics with EnjinCraft, so you may have to get creative with other plugins that can execute commands (such as a donation plugin).