Blank page won’t center and I can’t reduce font below 6
What do you mean by ‘center a blank page’? You can reduce font size by clicking in a text box where you normally change font and type number you want and hit Enter.
To center all text on a new page select the center icon or from the Menu Format > Alignment > Centred.
To set the font size below 6, which is considered the smallest that is easily visible, set the size in the Font selector to a figure below 6.