It doesn’t look like there’s any easy way to have a proper APA format header. It needs to say “Running head: TITLE” on the first page ONLY, then just “TITLE” on all pages afterward. How would I do this?
You can set the style of the first page (and thus header) independently of subsequent pages. This is done via Format > Page… > Header tab > uncheck Same content on first page. Alternatively you can make use of the First Page page style and use a different page style (e.g., Default Style or a new page style based on this style) for subsequent pages.