Group of users plugin

Hi, i am searching for a group of users plugin, with following functions:

A random user from the internet, who can create his OWN group, then publish it to the website and then others can join the group, if they want.

In the group, they may chat with each others.

Is there any plugins, where you can do exactly like this and works 100%?

I have been searching, but can’t find anything :/