There are three buttons in the top left corner of the Editor that let you switch between the Project Overview, Design Mode, and Interaction Mode. Each mode allows you to add and manage different features.
The Project Overview lets you view all pages or components for your current project. You can rename, duplicate, and delete pages and components in this mode. You can enter the Project Overview by clicking the Project button or the plus icon tab.
In the Project Overview, double click on any page or component to open it in a new tab.
Interaction Mode is where you'll add interactions, made from triggers and actions, to your designs. Read more about Interactions in Play here.
You can easily switch between open pages and components using tabs. Each tab has the name of the page or component on it, as well as a button to close the tab or share the tab. You can right click on the tab to rename the page or component, along with other options.