How can I get a quick overview of my executed tests?

In some interactive dashboards:

There are several ways to get such information. The easiest one is to use the Test Execution Overview dashboard available in the Tools tab or via a selected folder in the design tree:

Inside a document:

You can easily copy paste some information from the dashboards using the "Copy to clipboard" icon

There are also a specific dynamic section in Documents focusing on Test results. More info on Test Results section.