You can restrict content to sub-set of team members by using a private channel. This shows you how to set up a private channel and manage members.
Each channel in your team has a document library. You can add additional document libraries to a channel. This shows you how to do this.
A wiki allows Team members to create content directly in the Team, similar to a very basic webpage. This shows you how to add a wiki to a channel.
You can hold meetings in a Nexus365 Team. Meeting notes, document and online chat will be stored in the Team.