Size
- Try a combination of [Settings > Display > Font size] and [Settings > Display > Display size]
- Advanced : Enable Developer options and search for “Smallest width”. Default value is 360. Try changing it to 380 or 400. This value is a more granular control on display size.
Font style
Stock Android does not allow changing default font. However you can install 3rd party launchers that allow using custom fonts. Here is an article that references some of these launchers. One example is Lawnchair 2 (which I personally use).