In order to perform any calculations in Analyze, you need to either start a new project or open an existing one. A project is a set of one or more queries connected to a specific list of datasets. It can later be saved for reuse in the future or for sharing with other users.
A project can contain multiple tabs, each representing a separate query. Each query can use a separate data connection.
Dataset selection is not final - it can be changed at any moment for an existing project/query, therefore making it possible to repeat the same calculation with updated data or data from a different country.
Start new project
After you enter Analyze, click on "New project".
If you decide not to open a new project immediately after starting Analyze, you can do it anytime using the menu bar.