When you log into your account, some of these widgets are added here by default:
To add more widgets, select the desired tab and you'll see the Add Widgets option:
Click on the desired tab, and select Change Layout to view the available options:
You can also drag and drop widgets by hovering over the title of the widget. You'll also see the option to collapse or expand the widget:
To remove a widget, you can click on the "x" icon: