How to change the font size of the code you write?
Top left hand corner, click Editor, click the tab "Editor Settings".
It will bring up a window full of settings, automatically bringing up Interface Editor settings first. So just find "Code Font Size" and increase the font to your desire.
All your settings are there so change it to your preference. I like to keep my Display Scale at 125% and keep my font sizes high to not squint at everything I see.
Hope that helped!