Howdy Ralph,
I think you're looking for "Vertical spacing" options.
There are a couple of things you can do.
One is in Layout/Page Layout. There is a long "spring" on the far left, with a handle at the bottom. You can "grab" this "handle" with your mouse, and move it up or down, and everything shifts vertically in proportion. This is for multi-staff systems.
Second, (and perhaps what helps you better here) for default vertical spacing, you can find it at Format/Font Size and Spacing, and the lower "Vertical Spacing" options.
If the above don't answer the issue, just holler back
ttfn,
Sherry