h1, (Page Title): Type whatever you want to type here.

h2, (Article /Post Title): Select the type you want to style

h3, (Sidebar title): Maybe h1 subhead: From the dropdown select the headline, ie: h1, h2, h3, h4, or h5. H1 being the the most pronounced, like the title of the page.

h4, (Subheads): Think in terms of l hierarchie, hierarchical levels of importance.

h5, (Labels and inline subheads): Try to use as few levels as possible.
hr6, (Captions): A page is an h1 where an article would be an h2 and h3 would be used for sidebars

p, (Text/body): period