So, i want to create party plugin. is like factions , kinda. a party leader.. if the party leader enter a game the members do tooo. but i am trying to think of how to store the data of players in a party. like /party create ... how to create a 'party?' like, how would i know its members etc.
You should first create a "rough draft" code so we have something to help you with. You can't really ask us how to make something if you haven't attempted it, otherwise it's mostly just a plugin request. You should first try to code it yourself, and then ask about the specifics, not about the whole thing