When I create a new file, I see this screen[attachments file],
is there a way to change the part I checked with the red circle on the left?
The font metrics are calculated from the glyphs in the font.
Use the font information dialog to locate the glyphs with the highest WinAscent and lowest WinDescent.
CapsHeight is calculated from Capital H.
x-height is calculated from lowercase x.
You can set these font metrics through the Font Properties panel as explained here:
https://www.high-logic.com/font-editor/fontcreator/tutorials/font-metrics-vertical-line-spacing