Once you are inside of a team you will have entered what we refer to as the We Space. Here everything is in a shared space and is accessible to all of the team members and owners.
Upon entering the team, you will land in what is referred to as the General channel. Across the top, in the We Space, you will see Posts, Files, and either a OneNote Notebook or a Wiki. Depending on what type of team you are a member of will determine what other components of the We Space you will see. Assignments and Grades will be visible if you are in a class team. You will also see a plus tab at the top which will allow you as the team owner to add additional apps or websites to the channel for easy access.
One thing to note as we begin exploring more components and features of Teams is that each of the We Space features are available in EVERY channel. So thereby making every channel in the team completely customizable for your needs.