When you place your text cursor in a text item, the outer edge of the text item is shown with a dashed line and a soft blue outline.
You can also perform operations on the whole text object, by tapping on the blue edge. In this case the outer edge becomes a larger blue highlight to indicate the whole thing is now selected.
Once you have selected the whole text item, you can perform operations on the whole thing, for example:
To position a text item: Drag on the blue edge of the text frame.
To change the text box size: Drag any of the blue handles at the sides
To Copy, Duplicate or Delete the whole text item: Click the edge of the text, it becomes a darker blue, and a context menu will appear with the Copy, Duplicate, Delete options.
To change the style of all the text: You can select all the text in the frame or column in the usual way (Ctrl+A), or you can select the whole text object by clicking the edge. Now any Text Properties applied from the properties panel will be applied to the whole object.