This ain't actually a tut. for scripting, but since it has to do with adding lines in a script, so thought that this is the suitable place. Anyhow, this is how you change a font:
When you download a font, be sure to name it exactly as it's name is written in it's TypeFace name. To find out the TypeFace name of a font, double-click it and you'll see it's TypeFace name. If it's name is different from it's TypeFace name then rename it exactly as it's TypeFace name. Now copy the font into the Window's "Fonts" folder or if you're using Vista or 7, right-click it and choose "Install". Keep a copy of the font in your project's folder too. Then run RPG Maker VX and open Script Editor and scroll down to Main. Below begin command, write:
"Font.default_name = ["name of font"]
You can also write the following for messing with the size of the font and such:
Font.default_size = type size here
Font.default_italic = true/false to set italic
Font.default_bold = true/false to set bold
Font.default_underline = true/false to set underline
This is pretty basic stuff, but I'm bored, so who cares?
NOTE: Some fonts don't work with RMVX. For some reason, even if you add the lines correctly, the font won't appear.