Nix and NixOS are developed and used by a diverse and welcoming community from all around the world.
Check out what the community has made recently in the NixOS Weekly newsletter.
The official forum is the right place to get help from other users and discuss the development of the projects. There are also Announcements, Job offers and Events.
Another place to get in contact with other users is the official IRC channel:
#nixos on the freenode network (logs are available)
The NixCon Team organizes a conference once a year.
You can find announcements on Twitter or in the Forum.