A project is a playlist with all the songs, videos, presentations and other elements for your meeting. To add a new element you can drag it from the drawer, or drag a media file from the computer directly. Drag elements inside the project to rearrange them.
To navigate between elements you can click them or press the arrow down/up buttons on the keyboard.
When a show is in a project you can right click on it and click "Private", all private shows will have a lock icon and will not display in the shows list in the drawer. If that show has been added to any other projects it will also be private there, but any changes will show in all the projects.
Click the button in the bottom of the project area to add a new section. Here you can add titles for reference in your playlist, and add lots of notes.
Press CTRL/CMD + F to start searching in the drawer, and press enter to quickly add the first result to the current project.