Configuring Serenity’s one-page template is super easy and takes less than 1 minute.
Start by creating (or editing) a page.
Give it a title and assign it the One-page Template under the Page Attributes section.
Go to Settings > Reading.
Set Front page displays to A static page. Then from the drop-down, select the page you just assigned the One-page Template.
That’s it, you’re done!