Qgis is an application to process spatial data (geodata) which you can show in a map illustration.
The main tools can you find in the Menu Toolbar. The Layers Panel shows the layers of the current project.
The Manage Layers Toolbar helps you to add new layers. You can also add new layers with the Browser panel.
The project toolbar can be used to save your project. The Map Navigation Toolbar contains tools to navigate and zoom.
You can process your data using the Attributes Toolbar. Below the map illustration you can find the coordinates and the scale.