You can create a new channel by clicking "Create Channel" at the bottom of the Universe channel navigation. The only thing you need to do is input a name for your channel and press "Create".
Once the channel has been created, you can start adding the necessary sections to your channel. Just select the section you want to add, for example, "Files". Then either create a new folder or add an existing folder from your Google Drive.
The same applies to the calendar and hangouts sections. If you want to change any of these sections later, you can open the channel settings and toggle the settings on/off and change the source of the files and calendar.
If you don't need a section, you can hide it by opening the section and clicking the hide section button.