Some days ago i created a community about gangster theme. but i don't have a plot... son suggest me some fellas

A few quick ideas: 

-Godfather dies with no clear successor. Political and/or violent as the top men try to maneuver themselves to the position of power

-The big score: Feds, a bank, some private rich millionaire, etc., has a secret stash that is no longer secret. Now it's a race between gangs to try and find it. You could even flip it and make it a trap, but they won't know till it's too late (Mystery, detective, suspense, possible fighting)

-Revenge: Another gang took out a family member of the gang. Now it's payback time. Do they take the high road and just go after the gang? Or do they return the favor in kind, but with a higher body count. (You could also have another gang do it and somehow blame a different gang, in order to let their enemies kill each other) Paranoia and violence

-Games: Some friendly rivalries could be settled with a Mafia Olympics. Shooting tourneys, races, cop/fed protocol quizzes, economics, anything a little mafioso should know. A non-permanent way to show superiority over a rival gang. 

-Feds: The Feds keep cracking down on the gang. Any move the gang makes, the Feds seem to know beforehand. Is it a mole in the operation? Is someone trying to set the bosses up for a fall so they can move up? Lots of possibilities.  

-Old standards: Speakeasies, money laundering, protection rackets, bootlegging. Sometimes the oldies are goodies for a reason.

A drug deal gone wrong

Check the OOC forum for the "Writing Prompt" threads. They could be something you are interested in.

I'm having trouble thinking up a plot myself lol