The window: fonts, zoom, and help

Under autodoc --gui, the window draws in fonts you choose. Options › Fonts and zoom…:

In a terminal, the terminal's own settings choose the font and the size.

Options › Editor preferences… (SPC ,) sets the rest: the page's width, the theme, wrapping, line numbers, where each panel opens, the notifications' corner.

Help: F1 lists every key and what each needs; SPC h the notifications' history; this tutorial is Help › Tutorial….

More: Reference, Chapter 3: Modal Editor and Panels.