After selecting a Page you can then select from the available Sections and move them up and down in the list. This changes the order in which they appear in your Page.
In this worked example we are going to move the "Billing" section below the "Notes" section.
Click on the “Billing” section and click “Move Down” to move the “Billing” section below the “Notes” Section.
The “Billing” section is now below the "Notes" section.