To change the alignment, use the settings found in the Paragraph group.To change the font, the size or the color of the text, use the options from the Font group.Select it and, when the pointer becomes a four-headed arrow, drag it to its new placement. Release the mouse button when you’re happy with the size of the text box.
You’ll notice that the cursor has changed.As an alternative, you can press Alt + N to go to the Insert tab and then Alt + X to create a text box. Go to the Insert tab and, in the Text group, click Text Box.Select the slide where you want to add a text.