To increase or decrease the font size, go to 
(or
) Settings > 
Display and select Font size.
You can also increase the font size in (or) Settings > 
Accessibility and tick Large text.
How can I change the font size?
To increase or decrease the font size, go to (or) Settings > Display and select Font size.
You can also increase the font size in (or) Settings > Accessibility and tick Large text.