Can I set it so that there is a certain amount of space between the text on each page and the header?
I think you're asking about the header you can configure under "Headers and footers" in the "Page Settings" part of the format configuration. I.e. the small text that appears on the top of all or some pages.
The distance between the header text and the body text seems to be determined by the size of the top margin.
You can configure the top margin in the same place ("Margins" on the "Page Settings" pane).
I had to experiment with different top margins to get it right.
I assume the same goes for the footer text (e.g. page number).